Hueco Tanks' water-holding rock basins (huecos) and pictographs

Hueco Tanks State Historic Site contains thousands of natural rock basins called huecos that collect and preserve rainwater, forming isolated microhabitats. The site also preserves extensive Native American pictographs and archaeological evidence of millennia of human use. Hueco Tanks is internationally known as a premier bouldering area because of its unique, rough desert boulders and technical climbing problems.