Death Valley National Park is a remarkable place. The park is just east of the Sierra Nevada mountain range, placing it within a severe rain shadow. Rain shadows in the Sierra Nevada mountains are areas of extreme aridity that are caused by winds from the Pacific Ocean moving eastward across the landscape. Essentially, these oceanic winds contain a lot of moisture, but are forced to drop this moisture in the form of rain or snow as they climb the western side of the Sierra Nevada mountains. Above about 8,000 feet, the winds are drained of nearly all of the moisture they received from the ocean. Once these winds reach the eastern side, this process happens in reverse. The winds actually pull moisture from the atmosphere as they descend the eastern slopes of the Sierras. The rain shadow effect becomes more pronounced as elevation continues to drop. And Death Valley has some remarkably low elevations. Death Valley’s Badwater Basin sits at 282 feet below sea level; that’s the lowest elevation in North America. Yet less than 150 miles away sits Mount Whitney, the king of the Sierras; at 14,494 feet, it is the tallest mountain in the continental United States. Talk about an elevational shift.
Because of this rain shadow effect, Death Valley is incredibly dry. On average, the region receives less than 2 inches of annual rain. This sparse rain comes primarily in the winter, leaving the region bone dry for the majority of the year. Think of it as a reverse Portland or Seattle.
It is tempting to think that such extreme conditions would severely limit the biodiversity of the area. In reality, nothing could be further from the truth. This profound water scarcity has resulted in a plethora of adaptations in flora and fauna alike. 420 species of birds, 96 mammals, 63 reptiles, 16 amphibians, and over 1800 plants call one of California’s deserts home.
I visited Death Valley on April 2nd, 2016. I was on my way down to San Diego to visit my sister, who was due to have her baby any day. I just didn’t drive in a straight line. As luck would have it, all of these photos were taken on baby Nathan’s birthday.
I entered Death Valley from the Nevada side (I had taken a detour to see Tesla’s then-unfinished Gigafactory in Sparks, Nevada). From there, I crossed over Daylight Pass in California and cut westward across the park as the highway took me upwards of 4,000 feet and at times below sea level.
I took this detour to experience a rainy year in Death Valley. As I mentioned, Death Valley receives barely 2 inches of rain per year. But at roughly 10-year intervals, the region gets inundated with winter rains tied to the El Niño weather phenomenon. That year, Death Valley experienced 3 inches of rain in one 5-hour period. The rains were so intense that I had to change my route through the park; the road near Badwater had been destroyed by the rain!
Rain events like this do more than pummel parched asphalt; they awaken dormant seeds. You see, sometimes an area is inhabitable for no more than a few months every decade. That doesn’t mean it can’t be habitat. In the case of Death Valley’s tremendous diversity of wildflowers, many only get to see the light of day after these intense rains. Seeds lying dormant for years finally germinate (begin to sprout) when rain penetrates deep enough into the hard desert soils. The processes stimulated by the rain are continued by the warmer spring temperatures and abundant sunlight. In the springtime, an explosion of life colors the typically barren landscapes as wildflowers make their entrance. By the summertime, every wildflower will succumb to the punishing heat, winds and aridity. This brief window of life-giving time is by far their most pivotal. Intense competition ensues as the vast arrays of wildflowers vie for attention from pollinators. Those that successfully attract these pollinators are able to produce an abundance of seeds, which like their parents, remain dormant until the next significant rain event. While there are always a sparse number of wildflowers that bloom in Death Valley every year, most wait for spring conditions to be absolutely perfect.
By the time I had arrived in Death Valley, most of the low-elevation wildflowers had reseeded the soil and perished. It was only early April! Most of the flowers you see here are from high-elevation areas in the park, where temperatures were a tad more forgiving. I’ve decided that just before Nathan’s 10th birthday, I’m going to take him with me when I try this trip again.
Stay tuned for my next post, where I’ll look at how other plants and animals endure the desert on a daily basis. There’s more than one way to skin a cat.
Barbour, Michael; Pavlik, Brucel Drysdale, Frank; and Lindstrom, Susan. 1993. California’s Changing Landscapes: Diversity and Conservation of California Vegetation. A publication of the California Native Plant Society. Pages 7-10.
National Park Service. Death Valley National Park. 2016. Best Wildflower Bloom in a Decade. https://www.nps.gov/deva/learn/news/wildlowers-2016.htm
National Park Service. Death Valley National Park. 2016. Wildflowers. https://www.nps.gov/deva/learn/nature/wildflowers.htm#weatherandblooming
University of California, Merced. Yosemite and Sequoia Field Stations. 2019. Climate of the Sierra Nevada. http://snrs.ucmerced.edu/natural-history/climate
Jacob Ewald. April 2nd, 2016. Death Valley National Park.