The Eureka Dunes is a magical place. Depending on the season and the weather, it can be brutally hot, incredibly windy and cold, or warm, calm and quiet. I was hoping for the latter, and it worked out well. It had been a few years since I had driven the bumpy 10-mile road out there, but friends had been raving about the wildflowers there, and had posted photos on the web.
Eureka Valley is in the northwestern section of Death Valley National Park, and is surrounded by three mountain ranges. Most visitors know the valley from its dunes, which are most appropriately thought of as a “mountain of sand.” The Eureka Dunes cover about five square miles, and at 680 feet, are the tallest dunes in California, and probably the oldest in the western U.S.
Although many people think of sand dunes as hot, dry, inhospitable places worthy only of off-road vehicle riding, desert sand dunes are relatively moist habitats with a diverse array of unique plants and animals. Because sand is more porous than the finer-grained soils often surrounding dunes, water percolates down further, and is stored there like a sponge. Rainfall penetrates the sand, and the top dry layer insulates the water underneath from evaporating, leaving a reservoir to be tapped by sand dune plants, or psammophytes. Eureka Valley receives only 4-5 inches of rain in a “normal” year, but with sufficient early winter and continuing spring rains, the lower dune slopes may be bursting with wildflowers in the spring-as they are now.
With rains bringing flowers, the flowers attract insects. The white-lined sphinx acts as both pollinator (as an adult moth) and as an herbivore (as the larval caterpillar), devouring annual plants in great numbers.