The Ancients

United States' flag
North America » United States » California » Lee Vining
September 22nd 2011
Published: August 7th 2012
Edit Blog Post

Mono Lake shoreMono Lake shoreMono Lake shore

Tufa towers reflected in Mono Lake, one of California's classic photos.
I woke up this morning at Granite Lake Campground.

It sits on the shore of a lake in a glacial valley on the eastern side of the Sierra.

A little waterfall cascades down one of the peaks along the valley.

I chose this campground mostly because it’s close to Lee Vining.

In contrast with Upper Pines in Yosemite, the vegetation consists entirely of grass and the occasional small tree, and I got a spot by showing up.

It still has the bear boxes, though!

Driving out shows that Granite Lake is artificial.

The creek was dammed by the City of Los Angeles in the 1940s to feed the city’s growing thirst.

This had very important consequences for the surrounding area.

Further down the road, it reaches a broad open slope.

The area has no vegetation at all.

The other side of the slope contains a chain of what look like volcanoes.

They are the Mono Craters, the youngest volcanoes in the continental United States.

The last one formed a mere 700 years ago.

They were all generated by a rift
Granite Lake CampgroundGranite Lake CampgroundGranite Lake Campground

The glorious view from the campground
of magma which still underlies the eastern Sierra Nevada.

Finally, the road reaches Lee Vining.

As bad as gas prices are in Yosemite National Park, here they are even worse.

These prices are so high they exceed what I paid in Crater Lake (see A Day of Cascades).

Thankfully, I still have a descent amount remaining.

I can’t imagine how local residents handle it.

Mono Lake

Lee Vining sits on the western edge of a large area called the Great Basin.

It stretches from here across Nevada to central Utah.

The Great Basin contains a long series of mountain ridges running north and south, alternating with bone dry valleys.

This area gets less rainfall than anywhere else in the United States.

Notably, all rivers in this region evaporate without ever reaching an ocean.

During the last ice age, much of the area was covered by lakes.

The one that produced the Black Rock Desert (see The Lonely Road to Paradise) is typical.

Mono Lake, just east of Lee Vining, is the remains of one of those ancient lakes.

It got just enough runoff from
Mono CratersMono CratersMono Craters

One of the Mono Craters, the youngest volcanoes in the United States
the Sierra Nevada to counteract the constant evaporation.

It’s the second oldest lake in the United States at 760,000 years (Clear Lake, located in a fault rift north of San Francisco, is the oldest)

A National Forest visitors’ center in Lee Vining tells the story of the lake.

Notably, it is incredibly alkaline.

Salts eroded from the surrounding mountains flow in with the streams, and stay in the lake when the water evaporates.

It’s a thousand times saltier that the ocean.

One would think no life could survive in that water, but two species actually love it, brine shrimp and alkali flies.

Both of these, in turn, form a huge food source for birds.

The lake is one of the most important migratory stops for dozens of bird species, and several more nest here.

This lake has one of the highest densities of water birds in California.

Although the lake is most important ecologically for its birds, humans mostly know it for its tufa towers.

This tufa is a type of limestone.

The lake sits on the volcanic rift that underlies much of the eastern Sierra.
Mono LakeMono LakeMono Lake

Mono Lake seen from the visitor's center

That rift powers dozens of hot springs under the lake.

The hot water contains dissolved minerals.

Those minerals react with the alkaline salts in the lake to create tufa.

The end result is that a ring of tufa forms around the spring and then grows upward, layer after layer.

When it reaches the surface of the lake, the tower stops growing.

Mono Lake is filled with these towers, some of which grew in such density to form small islands.

Birds nested on the islands because they were safe from predators.

This unique ecosystem existed in relative harmony until the City of Los Angeles arrived in the late 1930s.

Los Angeles, then as now, is a huge metropolitan area existing in a relatively dry part of the country.

The city has an almost unfathomable thirst for water.

During the Depression of the 1930s, the city quietly bought water rights from the ranchers around Mono Lake.

When people started to resist, it announced a plan to take the rest by eminent domain using authorization from thirty years earlier (more on that tomorrow).

The local water
Save Mono LakeSave Mono LakeSave Mono Lake

Exhibit on the fight to restore water flow to Mono Lake
utility, which was exempt, saw an opening and formed a partnership with the remaining residents.

They then sold their water rights to Los Angeles for so much money that everyone involved could retire for life.

Los Angeles water engineers dammed all but two of the streams feeding Mono Lake (forming Granite Lake, among others) and sent the water southward.

While this took care of the local ranchers and LA residents, it has a disastrous effect on Mono Lake.

Without the stream flow to replenish water, the lake shrank and shrank from evaporation.

Huge alkali salt flats appeared where the lake once was.

The wind blew these around, creating some of the most hazardous air in California.

Even worse was the effect on the local wildlife.

As the lake shrank, the supply of brine flies shrank with it, causing immense problems to the local bird population.

Finally, as the water level dropped, what had been islands became peninsulas, and mountain lions started eating the nesting birds.

In 1974, David Gaines did a survey of the local bird population that revealed all these problems.

He forwarded it to the Audubon
Tufa TowersTufa TowersTufa Towers

Tufa Towers on the south shore of Mono Lake, from the parking lot

They, in turn, sued the city of Los Angeles to stop the water diversion and return the lake to a level that could support the ecosystem.

The city dragged out the trial for over a decade using every method they could.

Local residents became concerned that by the time the lawsuit came to trial, no lake would remain to defend, so they formed a group called the Mono Lake Committee in 1978.

The group started a statewide publicity fight, making ‘Save Mono Lake’ bumper stickers de rigueur for environmentalists.

The pressure worked and the California Supreme Court, the same group that allowed Los Angeles to use eminent domain forty years earlier, ruled in 1983 that the city must allow the lake to have a water level sufficient to protect islands used as bird nesting sites.

It wouldn’t be a Los Angeles water fight without subterfuge, however.

The city did everything it could to ignore the ruling.

Finally, another court order in 1995 required the city to allow specific water flows into the lake until the required level was reached.

Through gritted teeth, the city has followed the rules and the lake level
Eroded TowersEroded TowersEroded Towers

Close up view of tufa towers that have been exposed for many decades
is slowly rising.

It is still below the target level, but many consider the battle to save the lake won.

Ironically, the effects of the water diversion made the lake more of a tourist attraction than it had been before.

The lowered water level revealed hundreds of the tufa towers.

The most easily accessible are on the south shore.

Many lie along a nature trail (which has had to be rerouted as the lake level rises) with panels explaining the ecology.

The first part of the trail passes through sand and desert bushes, heading toward obvious towers near the water.

It reaches a sign indicating the original lake level.

Past it, the view does not change in the slightest.

It reaches another sign indicating the lake level required by the lawsuit ruling.

Again, the view doesn’t change, except that the towers and lake are much closer.

Soon afterward, the trail starts to pass tufa towers.

These are surrounded by bushes, and heavily eroded.

They have been exposed to air for decades.

The trail weaves through the towers and finally
Former tufa islandFormer tufa islandFormer tufa island

A former island of tufa in Mono Lake, now a peninsula
arrives on the lake shore.

The lake provides a haunting view, one of the most memorable in California.

The entire area looks like some alien landscape.

Narrow towers of white limestone rise from the water just off shore, perfectly reflected in the lake.

Distant mountains surround the shore beyond.

Seagulls float in the water.

One particular set of towers sits very close to shore with more visible in the shallow water.

These bubble, active springs.

The trail follows the shore for a while through a sea of grass.

Two large groups of towers sit in the distance, now surrounded by grass.

Before Los Angeles appeared, both of these were islands in the water and bird nest sites.

Part of the trail passes through a huge group of tiny files sitting on the edge of the water, the alkaline flies.

I then watched a bird go after them with open beak, running through them like a lawnmower.

Further along, the trail reaches a bay between the towers, with a wall of them visible in the lake
Tufa towers and brine fliesTufa towers and brine fliesTufa towers and brine flies

Another collection of tufa towers along the lake shore, wiith a large group of brine flies in front of them

These towers are active nesting sites.

Beyond them in the lake are water birds, as far as the eye can see.

I’ve rarely seen so many birds in one place in the wild.

This is why people fought so hard to save this ecosystem.

Leaving the shore, the trail weaves close to multiple large towers further inland.

All of them look like narrow walls of crumbly rock.

The color ranges from white to grey.

Signs mention to keep off, because they are surprisingly fragile.

The rocks are also quite sharp.

Past the towers, the trail reenters the desert bushes and ends up back at the parking lot.

Panum Crater

The road back to Lee Vining passes what looks like a small volcano near the lake.

A network of poor quality unsigned dirt roads heads toward the mound.

The only thing that marks the preferred road is it being somewhat wider with fewer potholes, plus a tiny sign.

After such things as the Upper Shore Road (see California Coast and Open Road) it was easy enough to drive.

Water birdsWater birdsWater birds

A small sampling of the hundreds of birds floating in Mono Lake
road ends at a trailhead next to the volcano, Panum Crater.

A signboard mentions that it formed when magma met a pool of underground water which exploded into steam.

The upper rock layers literally blew up.

It formed only 700 years ago, making it the youngest in North America.

The sign also mentions the reason the road is so poorly marked, to discourage rock collectors.

The volcano contains some of the rarer rock types in the United States, which collectors love to take away.

When hiking here, leave the landscape alone!

The trail starts by climbing straight up the obvious mound.

Like the rest of this landscape, it has desert bushes and little else.

The trail appears to be mostly sand, but it’s really eroded volcanic rocks.

It finally reaches the top, on the rim of a huge bowl.

A wide mound appears in the middle, covered in sharp twisted rocks.

The rim provides a huge panoramic view of the surrounding area, nearly all desert.

The Mono Craters stretch off to the south, and the eastern slopes of the Sierra Nevada dominate the west.
Panum CraterPanum CraterPanum Crater

View of the side of Panum Crater, with Mono Lake in the distance

These mountains contain little greenery, a huge contrast to the western slopes.

The volcano blocks the view of Mono Lake to the north, though.

From the rim, the trail drops into the bowl, and the climbs the side of the mound.

Once on the mound, it passes large amounts of unusual rocks.

These rocks are different to the last volcanoes I climbed, at the Craters of the Moon (see Hell’s Acre), because they formed through a different process and have different mineral content.

At Craters of the Moon, the lava flowed over the surface and cooled slowly.

Here, it mostly flew through the air as globs and cooled quickly.

It also has a silicon content of over 75%!,(MISSING) the same mineral used to make glass.

The most prominent rock is light grey and looks like a stone sponge, pumice.

The lava trapped air bubbles because it cooled so quickly.

This rock is so light it floats in water!

Mixed in with them are black glassy stones.

These are obsidian, volcanic glass.

It forms when lava containing
Lee Vining CanyonLee Vining CanyonLee Vining Canyon

View of Lee Vining Canyon, heading for Yosemite, from Panum Crater
high amounts of silicon and iron quickly cools on the ground.

Obsidian is the most highly sought after of all volcanic rocks, both historically and currently.

Ancient humans wanted it because it breaks with an incredible sharp point, making it the perfect material for arrowheads and spears.

Modern rock collectors want it due to its look.

Finding specimens as large as some of the ones near the trail is incredibly rare; they likely survived only due to the area’s isolation.

The trail finally reaches the rim of the volcano, a wall of narrow jagged rocks standing on end.

It passes through a gap to reveal a large bowl of broken jagged rock.

Unlike the aa rocks at Craters of the Moon, these rocks clearly broke apart.

The bowl is absolutely filled with them.

More big pieces of both pumice and obsidian poke through the rocks.

Desert weeds grow in cracks.

The rocks radiate heat, so the bowl is noticeably hotter than the already hot desert outside.

A scramble path weaves into the bowl, but it has treacherous footing.

I turned around at this
Obsidian and pumiceObsidian and pumiceObsidian and pumice

The two most famous rocks at Panum Crater, obsidian (above) and pumice

Owens Valley

Back at Lee Vining, I drove south.

This brought me into the Owens Valley.

The valley sits sandwiched between two of the tallest mountain ranges in the United States, the Sierra Nevada and the White Mountains, both of which rise above fourteen thousand feet.

Measured from the valley floor to the tops of the surrounding peaks, it is the deepest valley in the world.

Since the valley sits in the Sierra rain shadow, it gets relatively little precipitation.

Most of the floor is covered in scrub and bushes, with pine trees further up the slopes.

While this leads to a hot and windy drive, it also provides incredible views.

Unlike the view of granite peaks through canyons on the western slopes, here the Sierra Nevada stretch along the valley like a long granite wall.

It very much reminds me of the drive through Jackson Hole (see Those peaks).

On the other side, the White Mountains do appear white, partly from snow.

Eventually, I reached through the town of Bishop.

It’s the second largest town in the area.
Crater RimCrater RimCrater Rim

Sharp rocky walls on the crater rim. These rock layers litteraly blew up when hot lava hit a water pocket

Importantly for me, it has the most reasonable prices in the valley for supplies.

I filled up my tank here.

The price, I need to note, was still twenty five percent higher than what I paid in Sonora (see Gold Country).

I also bought something very important for the next part of the trip, two gallons of water.

I’m heading deep into the desert soon, and that water makes the difference between surviving a breakdown and death.

Further south, the road reaches the town of Big Pine.

On the south side sits a road junction next to a campground and a truly odd pine tree.

A signboard next to the tree notes that it is an eighty year old giant sequoia!

Local boosters planted it in the 1930s to commemorate the opening of the highway I’m about to drive, Westguard Pass.

From the junction, the roadway heads east, quickly entering a narrow canyon.

Unlike those seen earlier, this canyon has no trees whatsoever.

It does have jagged walls of basalt, so familiar from the Cascades.

At one point the walls
Panum Crater insidePanum Crater insidePanum Crater inside

The inside of Panum Crater, all jagged broken rock
close in and the road becomes a single lane.

Jagged basalt outcrops fly by close to the car.

Thankfully, this area passes quickly.

Ancient Bristlecone Pine Forest

Further up, the rocks change.

Now, the canyon walls are lined with piles of little crumbly rocks with a light tan color.

These are dolomite, another type of volcanic rock.

It forms most of the White Mountains.

The rock looks white from a distance, hence the name of the range.

The dolomite has a huge affect on the type of plants that can survive here, because it has almost no ability to hold water.

Little precipitation falls here thanks to the Sierra rain shadow, but what does fall quickly drains away.

People can be forgiven for thinking that nothing at all can grow on this rock, but at least one tree species has evolved the means to do so.

After the road climbed from the canyon, it entered a relative flat space at the southern end of the mountain range, Cedar Flat.

This area is covered in widely spaced trees.

They look like pine
Owens ValleyOwens ValleyOwens Valley

The Owens Valley, once a productive agricultural region until Los Angeles took all the water
trees, except that the needles are all wrong.

These trees have little needles growing in clusters, giving branches the look of a bottle brush.

They are called bristlecone pines, and are found throughout the Great Basin.

They have wide and very shallow root systems, allowing them to absorb literally every drop of moisture that falls.

After a while, the road forks.

I took the left branch into the heart of the White Mountains.

Soon enough, it starts to climb.

This road is narrow with steep slopes and tight curves, the most difficult I’ve seen in California since the drive to the Pinnacles (see California Beach Culture).

The early part shows only the lower slopes of the mountain I’m climbing; with a view of dolomite, the trees, and little else.

An overlook then shows part of the Owens Valley to the west with the Sierra behind it.

The road continues to twist steeply upward.

A view appears to the east of the Silver Peak Range, the next mountains over in the Great Basin.

The road climbs some more with more overlooks.

The bristlecone pine trees continue to appear.

Dolomite slide on the way up the White Mountains

Oddly enough, their size stays roughly the same.

Most trees shrink as elevation climbs thanks to the harsher conditions at higher altitudes.

The road finally gets close to the top of the mountain, and the REAL view appears, the Sierra View Overlook.

The drive is almost worth it for just this alone.

The highway has now climbed over nine thousand feet, the highest paved road in California, and the view reflects it.

To the west, the Owens Valley stretches a long way far below, with the wall of the Sierra Nevada beyond it.

Mount Whitney, the highest peak in the continental United States, appears at the left end.

It is hard to spot because its neighbors are also quite high.

To the east, the mountain ridges of the Great Basin stretch into the distance.

To the south, more mountains appear, all covered in bristlecone pines.

After the view, the road rolls along the side of the mountain ridge.

It finally reaches a narrow valley, and a surprise.

A spur road goes to a rather large parking lot for such a remote
Sierra View southwestSierra View southwestSierra View southwest

The southern Sierra Nevada from the Sierra View Overlook
location, next to a trailer with the Forest Service logo on it.

A sign states “Welcome to the Ancient Bristlecone Pine Forest”.

The trailer is the replacement for the original visitors’ center, which burned down.

It has an exhibit on what makes the trees here so special.

Like redwoods (see Big Trees), bristlecone pines contain a resin that make them resistant to insects, rot, and environmental damage.

That resin, combined with their wide root system, is how they survive in this harsh environment.

Ironically, the harsher the environment, the longer lived the tree.

The bristlecone pines on the lower slopes get enough nutrients that they add tree rings of a few millimeters a year.

These rings spread out the resin and the tree dies in a few hundred years.

At this elevation, each tree adds rings that are practically microscopic and filled with resin.

The thick resin makes these trees practically immortal.

Nothing in the natural environment can kill them, and they live for many thousands of years.

The oldest are over five thousand years old, meaning these trees were alive at the time the Egyptians built
Sierra View northwestSierra View northwestSierra View northwest

The northern Sierra Nevada and Owens Valley from Sierra View Overlook
the Pyramids!

On top of that, once the tree does die, the wood doesn’t decay, so a tree that looks like it died yesterday can be as old as the last ice age!

While the Great Basin has large numbers of old bristlecone pines, the ones on these slopes rank as the oldest of them all.

The high elevation, nasty winter winds, and ice storms ensure the slow growth needed to survive for millennia.

They were discovered, of all people, by climate scientist Edmund Shulman in 1953.

He was a leading practitioner of dendrochronology, using tree rings to study the history of earth’s environment.

Shulman began his research with giant sequoias.

They were not old enough to cover the period he needed.

He then tested the bristlecone pines on the lower slopes, and they were still not old enough.

He steadily moved up the White Mountains until he found the trees in this valley and hit the jackpot with a tree nearly five thousand years old.

Even that tree wasn’t enough to cover the time period Shulman wanted, so he started testing dead trees.
Silver Peak RangeSilver Peak RangeSilver Peak Range

View east from the White Mountains, showing the Silver Peak Range

Remember how dead bristlecone pines don’t decay?

Their tree rings overlapped the data from live trees.

Matching up the rings proved that dead trees have been in this forest for many tens of thousands of years.

He ultimately matched up the tree rings between different dead trees to produce an environmental timeline extending back over a hundred thousand years.

A decade later, these ancient trees had an even bigger scientific impact.

At the time, archeologists had starting using a new science called radiocarbon dating on ancient artifacts.

Carbon atoms are the basic building block of organic matter.

They naturally exist in nature in two variants, one with fourteen particles in the nucleus and one with twelve.

Carbon 14 is radioactive and slowly decays into carbon 12.

By precisely measuring the ratio between the two, archeologists can work out how old something is.

At the time, scientists knew something was wrong with the method.

They were getting dates for known artifacts that did not match up with the historic record.

Trees absorb carbon atoms from carbon dioxide the air.

At the
Shulman GroveShulman GroveShulman Grove

The Shulman Grove of bristlecone pine trees
time, people believed that the ratio of carbon 14 to carbon 12 in the air was constant.

C. W. Ferguson, who had studied under Shulman, realized he could test this belief with the bristlecone pines.

Counting the rings would give the precise age of a given part of the tree, which can be compared to the age given by radiocarbon dating.

Radiocarbon dating parts of these trees conclusively proved that the ratio of carbon 14 to carbon 12 in air varies, sending shockwaves through scientific archeology.

From the trailer, a trail goes up the hillside through the trees.

Hiking it is at first mildly disappointing, then disconcerting, and finally profound.

The trail passes some little trees that except for the odd needles could be Christmas trees.

They have cones and needle covered branches just like other pine trees.

These particular trees, which look so young, are hundreds of years old.

Hollywood plastic surgery has nothing on bristlecone pines!

Further along, the trail passes a fallen log.

It looks just like the kind of log found on the side of a trail in a pine forest,
Young bristlecone pineYoung bristlecone pineYoung bristlecone pine

This tree is over a thousand years old!
not at all remarkable.

Shulman dated that log, and found it has been sitting on this hillside for almost six hundred years, before Christopher Columbus sailed.

It looks like it fell yesterday.

Hiking here requires a change in perspective.

Slowly, the idea sinks in that this forest is truly ancient, the oldest living things on earth.

Young trees are ten times as old as the oldest humans.

This landscape has looked the way it does now for tens of thousands of years, and some of these trees witnessed a large portion of it.

Compared to that history, the human lifespan is a mere blip.

Being in their presence becomes a profound experience.

Truly ancient bristlecone pines look grotesque.

What can kill something that is nearly immortal?

One careless human with a hacksaw certainly can, but many old trees die due to winter wind.

The wind blows ice, which breaks and strips off the bark.

These trees can compensate, by redirecting nutrients to the portion still alive.

Ancient bristlecone pines consist of a few green branches attached to a
Fallen bristlecone pinesFallen bristlecone pinesFallen bristlecone pines

These logs have sat on this hillside for over four hundred years
wind twisted mass of dead wood.

They look like no other trees on earth, gnarled survivors of all nature can throw at them.

After the last branch dies, the tree remains standing, the wind slowly stripping the wood away.

The trees also die due to erosion.

Dolomite is crumbly, so it slowly erodes with each rare rainstorm.

The trees have shallow root systems.

If too much soil around the roots disappears, the tree will topple over and die.

The trail passes a tree where half the roots are now in open air.

Soil from further up has accumulated on the other side of the tree, just enough to keep it upright.

Scientists have measured the erosion rate, roughly an inch every thousand years.

This particular tree is over four thousand years old.

The final part of the trail crosses a hillside with no vegetation.

It’s covered in little pointy chunks of dolomite, the remains of a rockslide.

It gives a huge view of this part of the White Mountains, covered in bristlecone pine trees, with the Sierras in the
Ancient bristlecone pineAncient bristlecone pineAncient bristlecone pine

This tree is over four thousand years old
distance beyond.

From here, it passes a memorial to Shulman and returns to the parking lot.

I got back to the Owens Valley after dark.

Since the valley has few trees and no large towns, a glorious carpet of stars covered the sky.

This is my best sky view since the Badlands (see Welcome to the Geology Freakshow).

Sierra Hot Springs

I ended my day with an exceptional treat.

Thanks to the volcanic rift under the eastern Sierra, this region has one of the highest concentrations of hot springs in the United States (see A Day of Cascades).

All of the larger ones have been turned into resorts.

The remainder are treasured local secrets, rock formed pools deep in the wilderness along unmarked dirt roads.

With internet research, I managed to find one located near Big Pine (which I’m not linking to; do your own research!)

Visitors to these springs should know some rules.

They are maintained by volunteers, so remove all trash.

Not everyone is this considerate, so expect to see some junk.

Locals patronize these springs heavily, so check out the scene from a
Ancient bristlecone pineAncient bristlecone pineAncient bristlecone pine

Another tree that was alive when the Egyptians built the pyramids
distance before joining in.

Nudity is VERY common.

Spring temperature varies, so test them before jumping in.

At night, always wear a headlamp.

Finally, hot springs harbor bacteria, so keep nose and mouth out of the water.

Finding the first turnoff was easy enough, a wide dirt road heading into the Sierra foothills.

The problems began soon afterward.

A network of dirt roads leads off from this first road through desert scrub, and none of them are marked.

The springs are along one of them, somewhere.

I drove them for at least an hour, stopping at every depression with big clumps of reeds.

None of them held hot water.

I ended up using the stars overhead to find my way around.

Just when I was about to give up, I heard a trickle of water.

It was hot!

I parked the car and followed the little stream.

It reached a spur road.

I drove down it, and soon found a dirt parking lot.

Next to it was a pool formed by little rocks, the spring.

Unbelievably, I had
Ancient Bristlecone PineAncient Bristlecone PineAncient Bristlecone Pine

Another look at nature's ultimate survivors
it to myself.

My soak tonight was almost as close to heaven as a human can experience on earth.

The water temperature was absolutely perfect, warm without causing much sweat.

The crisp air provided the perfect contrast without being cold.

The carpet of stars overhead completed the picture.

I wanted to just lay there and drift off to some wonderful, peaceful place.

My guidebook warns that a perfect Sierra soak ranks as one of the world’s great addictions, and leaving can be nearly impossible.

I now know exactly what that means.

I only left, reluctantly, when I felt the light headedness that indicates the onset of overheating.

Aside from that, I could have stayed there until the sun came up!


Tot: 0.183s; Tpl: 0.026s; cc: 21; qc: 48; dbt: 0.0119s; 1; m:saturn w:www (; sld: 1; ; mem: 1.5mb