The Islands of Interior California: The Littlest Islands of All

Red Hill with the southern Sierra Nevada in the distance

How often in life have you stepped back from the rat race and considered your life and your place in the cosmos? Wondered why you are here and what does it all mean? Do your conclusions and philosophy change over time? Or is life just such a rush that you deal with it, and look back and wonder where all the time went?

If there is one thing we learn as we delve into geology, it is that time is a relative thing. We look at someone a hundred years old, and we think of a century as a very long time. And yet a human lifetime is miniscule in the face of geologic time on earth. The world has existed for 45 million centuries. Whatever his other failings, Richard Dawkins put our existence into perspective nicely:

"After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with color, bountiful with life. Within decades we must close our eyes again. Isn’t it a noble, an enlightened way of spending our brief time in the sun, to work at understanding the universe and how we have come to wake up in it? This is how I answer when I am asked—as I am surprisingly often—why I bother to get up in the mornings." 

With that idea in mind, can you imagine how ancient we humans would look to a creature that lives an entire life within maybe three or four weeks? That's where we find ourselves today, within the smallest of California's "islands". By "islands", I'm referring to the isolated sources of water within one of the harshest deserts in the world, Death Valley and the surrounding Basin and Range Province.

Red Hill (top picture) is a cinder cone and associated basaltic lava flow situated between the Sierra Nevada and the Coso Range south of Owens Lake. The lavas are tens of thousands of years old, maybe even several hundred thousand. This area is desert today, but several times in the last two million years global cooling radically changed the climate in the region. Meltwater from the Sierra Nevada glaciers filled Mono Lake Basin and Owens Lake to overflowing, and the resulting river flowed south towards China Lake and ultimately to Death Valley.

Water is a rare phenomenon at Fossil Falls. This is a shot from several years ago on a very wet trip.

Lava spilled out across the valley floor and blocked the flow of the ancestral Owens River, and the river formed a 40 foot tall waterfall. Over time erosion attacked the lava, causing the lip of the fall to migrate upstream. Pebbles rolling in the current started grinding out potholes in the lava, some small, and some more than ten feet deep. When the climate warmed up during the last 10,000 years, the river dried up and only the potholes and abandoned waterfall remain. It's a fascinating place to explore.

But islands? The small potholes have their own kind of story, one of the persistence of life in the face of the harshest conditions imaginable. The potholes are natural collection sites, capturing windblown dust and silt as well as seeds and most importantly to this story, the eggs of small creatures, possibly carried in the mud adhering to the feet of birds. During storms water collects in some of the potholes (very small islands of water in the midst of a desert). I can imagine the birds finding water in the potholes and stopping for a drink, with the eggs washing off in the water...and eventually hatching.

Within these pools are complete ecosystems of creatures who must live their entire lives on a scale of a few weeks. It begins with birth when a pothole is filled with water and ends in death when the water evaporates. The creatures include small fairy shrimp and what I assume are ostracods, small bivalved crustaceans. These animals are the distant and yet direct descendants of the first complex forms of life that evolved on this planet some 500 million years ago, creatures like trilobites and sea scorpions. Their original ancestors were creatures of the sea, requiring water to survive. They still require water today, but water is a precious and rare commodity in the desert environment. To survive, these descendants evolved eggs that could survive years of desiccation in a harsh desert environment.

One could speculate in a slightly humorous vein that these creatures don't have a whole lot of time to consider their place in the cosmos, and don't have much of a chance to ask themselves why they exist when life is compressed to a few weeks at best. But consider how short our lives are in the face of vast time across the Universe. Are we all that much more aware of ourselves?

A Fairy Shrimp (carrying an egg sac). The "sesame seeds" are Ostracods, very small bivalved crustaceans who were in constant motion.

This is the first installment of a mini-blog series about the biological islands of interior California, an exploration of the geological conditions that allow life to survive in the harsh deserts in the vicinity of Death Valley National Park. Fossil Falls is readily accessible to travelers on Highway 395 between Ridgecrest/Inyokern and Lone Pine. The one mile gravel road is a few miles south of the rest area at Coso Junction and just north of Little Lake. The falls themselves are at the end of a quarter mile walk across the lava flow. A small and decidedly barren campground is nearby. In addition to the potholes and falls, explorers can also find petroglyphs and small shelters where Native Americans carved arrowheads and spear points from obsidian.