A Day on the California Prairie: Finding the Precious Places Near Home

Yosemite National Park is closed. The coastline is closed. The state parks are closed. Am I complaining? Not in the least. We are facing an unprecedented threat, so we must curtail our freedoms a bit until the scientists and the doctors (and all of their heroic support staff from nurses to foodworkers to custodians) can do their work protecting us. And we must continue to do our part, isolating ourselves from each other, and from the virus itself. I pray that you are able to stay healthy and safe, and if tragedy strikes, that you find peace in some way.

In the meantime, there are a few legal ways to maintain sanity. Exercising in isolation from others near home is one way. If the city parks are crowded, find a deserted road on the edge of town to walk along. It is a way that we can find the precious and undiscovered treasures that have always been just outside our towns. As it turns out, some treasures are ephemeral, lasting only a few weeks.

My town lies on the edge on one of the few remaining largely untouched prairies left in California. These prairies used to extend across the entire Great Valley, but agricultural development has displaced 95% of the grasslands. There are a series of wildlife refuges up and down the valley that protect some of the remaining wildlands or rehabilitated farmlands. The rest of the prairie tends to be found on the margins, in the foothills of the surrounding mountains where the soils are too thin to support agricultural development.

The rainfall this year has been perilously low, with not a drop in the entire month of February. But March and April saw a resurgence in precipitation and the drying sprouts reawakened, and flowers have appeared in abundance throughout the Sierra Nevada foothills.

We took a drive through the prairie that remains between the Tuolumne and Stanislaus Rivers, and were treated with an explosion of color. I'd love to say I was an expert botanist and tell you all the species, but beyond lupines and poppies, my knowledge of flowers is sadly lacking. What I enjoyed today was the profusion of color.

We are living in one of the most challenging times many of us will ever experience short of all-out war. Natural disasters horribly affect particular regions, but there is always help from elsewhere, and there are places of retreat and refuge if an earthquake or hurricane strikes. But this one is a worldwide viral attack, and all we can do is shelter in place until it passes. It's scary, it's dangerous, and many are suffering. I hope there are a few moments of peace and serenity to be found here in these little treasures close to home.

Tales from the Semi-Super Bloom Tour, Part 5: Coming Home

"We shall not cease from exploration

And the end of all our exploring

Will be to arrive where we started

And know the place for the first time.

Through the unknown, remembered gate

When the last of earth left to discover

Is that which was the beginning..."

T.S. Eliot

I'm a bit behind, what with the end of the semester and all that, but there was a bit of unfinished business from a few weeks ago...the end of our Semi-Super-Bloom tour. Yes, most of the flowers throughout the west have faded and shriveled as April turned out to be very dry. In this wet year many parts of California were covered by flowers in a way not seen in a decade or more. It was a spectacle and hundreds of thousands of people converged on places like Anza-Borrego, or Elsinore, or the Grapevine in Southern California. Among the crowds there were the stupid and ignorant who trampled the flowers and in one instance landed a helicopter in a field of flowers.

Around six weeks ago, Mrs. Geotripper and I set out to find some of the less crowded places, the spots where the flowers were blooming, but they weren't quite at the level of the Super-Bloom. Our journeys carried us through the Mojave Desert, Death Valley National Park, the Merced River Canyon downstream of Yosemite, and the Red Hills Area of Critical Environmental Concern. But it was our final journey of the tour that was so illuminating: we were home. And it was a beautiful place.

We live at a nexus point, the boundary between the Sierra Nevada and the Great Valley of California. Our town is surrounded by agricultural fields, but as we drive east, the fields and orchards give way to one of the few remaining prairies in the state of California. Although large portions are being plowed over for almond orchards, the grasslands still exist in the low foothills of the Mother Lode.

The soils are old and deeply weathered, and are generally nutrient poor. It's only a few feet to bedrock as a rule, so water is not often available for plant growth, and so for most of the year the hills are covered with a brown (some say "golden") veneer of dead grasses.  But in the spring of wet years, the prairie comes alive with color. One of the unique habitats of our grasslands are the vernal pools, the hollows where water stands for a few short weeks or months in the spring. Because they are flooded part of the year and dry for the rest, they are a crucible for the evolution of unique plants and animals adapted to the harsh environment. Many of California's endemic plants are found there. There are hundreds of these vernal pools scattered across the prairie. And that's where we saw much of the color as we drove through a few weeks ago.

We were traveling on Willms Road south of Knight's Ferry on the Stanislaus River when we spotted one of California's near-endemic bird species. Red-winged Blackbirds are a familiar sight across much of North America, but there is a closely related species called the Tricolored Blackbird that is mostly found in the Great Valley and in the prairies of the foothills (they have a white stripe below their red wing spots). The birds are endangered because of an unfortunate habit they have of nesting in large colonies in the middle of grassy prairies. The problem is that they don't make a distinction between a tall-grass prairie and an alfalfa field, and thus thousands of nests and their occupants have been destroyed in an afternoon as farmers cutting and harvesting the alfalfa. Efforts are being made to reimburse farmers who wait a few weeks to harvest, giving the young birds a chance to mature and fly away.

We were home, and we found exploring the back roads just beyond our backyard to be just as colorful and wondrous as our thousand mile journeys into the deserts and beyond. Never stop exploring, and never be trapped into thinking that you have to go vast distances to see wondrous things.

Driving Through the Most Dangerous Plate Boundary in the World: A Landscape Buried in Hot Mud, and a 6-foot Long Saber-tooth Salmon

Mt. Shasta is a big mountain. A really big mountain. Reaching an elevation of 14,179 ft (4,322 m), and rising nearly 10,000 ft. (~3,000 m) above the surrounding terrain, it has a volume of around 100 cubic miles. As such, it is the biggest volcano in the Cascades volcanic arc, and probably is on the short list of largest stratovolcanoes in the world (shield volcanoes like those of the Hawaiian Islands have a different origin and are much, much larger). The volcano is the surface manifestation of the sinking of the Pacific lithospheric plate beneath the North American continent along the Cascadia Subduction Zone. As the plate sinks deeper, superheated water is liberated, which lowers the melting point of the deep rocks, forming magma chambers that sometimes erupt at the surface.

The thing is, one would think that this massive edifice would be made of lava and volcanic ash, but a large percentage of the volcano is actually composed of...mud. Simple mud. Well, more properly, mudflow deposits, or lahars, as they are called by geologists. This isn't the kind of mud you find on the bottom of a lake or the sea. It was mud born of violence. The mud includes massive boulders, showing that the formation of the lahars involved the rapid melting of snow and ice during violent eruptions. The mixing of water, ash and rock fragments forms a slurry that moves quickly down the flanks of the volcano. To humans, they are dangerous. A lahar in Colombia in 1985 killed around 23,000 people in a matter of minutes.

On our journey through the most dangerous plate boundary in the world, we've explored the accretionary wedge and forearc basin of the massive subduction zone that once existed off the California coast, and now we've reached the base of the most visible part of the system: the magmatic (or volcanic) arc . The arc is extinct today in this part of California, but one is still active in the Cascades of Northern California and the Pacific Northwest.

Driving through the foothills of the Sierra Nevada in places like Knight's Ferry or LaGrange, just north of the Yosemite National Park region, it's hard to visualize the violent past of this landscape. The gentle slopes belie the intensity of the floods and flows that carried the boulders for forty or fifty miles from the volcanic centers that once existed near the crest around Sonora Pass and the Dardanelles. The rocks are called the Mehrten Formation, and they were deposited around 5 to 7 million years ago, when the subduction zone was still active at this latitude. Similar mudflow deposits cover much of the northern Sierra Nevada.

Of course, the volcanoes weren't always erupting. Decades or centuries may have passed between eruptions, and the tattered ecosystem would recover. Petrified wood has been found in the formation, and fossils of horses, camels, and other animals that lived on the river floodplains emerging from the mountains above. A few years ago I became aware of some of the most unique fossil species to be discovered in the formation, gigantic tortoises, and six-foot-long salmon...with fangs! The Sabertooth Salmon (Oncorhynchus rastrosus) once swam the ancestral Stanislaus and Tuolumne Rivers, right here in my own back yard. That's almost as cool as living in a place that once had Mosasaurs (oh yeah, they lived here too).

A former student of Modesto Junior College (and current geology major at CSU Stanislaus), Jake Biewer, is working this summer on a new exhibit at the Great Valley Museum highlighting his research on the Sabertooth Salmon and the large tortoises of the Mehrten Formation. I'm looking forward to seeing the results!

In our next post, we'll discover what it's like to be living beneath the volcano. In the meantime, check out this video of a lahar at Mt. Shasta.

Biblical Plague or Culinary Opportunity? A day in the California Prairie Lands

We journeyed out to the California prairie lands again today. We've now paid a visit in the fall, the early spring, and now the late spring, as summer starts to take hold in the Sierra Nevada foothills. Our destination was a small stockpond in the hills south of Knight's Ferry on the Stanislaus River. The local bedrock is composed of vertical exposures of metamorphic slate and greenstone with a covering of andesite lahar (volcanic mudflow) deposits called the Mehrten Formation.

We had one of the best rainfall seasons in many years, with around 115-120% normal rainfall, and an unusually cool April and May. When we were here in early April, the ground was muddy, and the grass was green. There were quite a few birds, but when we got there this evening, it was a great deal busier, even though the grass is brown. Part of the busy-ness involved things being splattered on the windshield and being crunched under the tires. There was a regular plague of grasshoppers, thousands upon thousands of them everywhere. Apparently the conditions were ripe for a population explosion.

I've heard of some serious problems with grasshoppers in the midwest this year, with aerial spraying of pesticides and the like, but I don't think it was going on here. There was a much more normal way of dealing with the overpopulation of the pest: birds were munching away! I'm not entirely sure why the birds were all lined up, but there was a small drainage next to the road, and I suspect the grasshoppers were more abundant on the particular stretch of road.

It's kind of creepy to get out and walk among the insect plague, as hundreds jumped away in all directions. I leaned down to take a shot of a bee in one of the few flowers, and I honestly did not notice the grasshopper looming over the flower. In fact, if you look carefully, you may notice that at least four grasshoppers were stripping away the leaves and flowers.

Still, it was peaceful in the twilight, and the songs of hundreds of satiated birds and bullfrogs was a pleasant musical accompaniment to the dying sunlight.

UPDATE: I suspect we saw an 'irruption' of devastating grasshoppers. Apparently they have caused some real problems in the past, especially in the late 1950's.