Clark Mountain Natural Arch in San Bernardino County, California
Photo by Jay Wilbur
NABSQNO 11S-628480-3934280. Clark Mountain Natural Arch is a buttress natural arch eroded through basalt. It is located on a northward radiating ridge of Clark Mountain, in the Mojave National Preserve, San Bernardino County, California. It has a span of about 20 feet and a height of about 40 feet. There are some smaller arches in this same ridge to the south, i.e., above Clark Mountain Natural Arch.