Bureau of Land Management, California.
Marble Mountain Fossil Bed contains one of the classic Cambrian trilobite fossil sites within the Western United States. The Marble Mountain Fossil Beds lie in a beautiful shale formation that is 60-feet thick and over 550 million years old. Trilobites were small marine crustaceans that resemble modern-day horseshoe crabs. Trilobite refers to the three long spinal sections of the skeleton. Trilobites are extinct arthropods that disappeared approximately 250 million years ago. You may collect a reasonable number of invertebrate fossils and rocks for personal use without a permit and free of charge of BLM lands. Personal collections cannot be sold or bartered for personal gain, and commercial collecting is not allowed without a permit. Only hand tools may be used; explosives and power equipment are not allowed. Collecting may not be allowed in special management areas, such as wilderness and national historic sites or on mining claims.
From Needles, CA, take I-40 west approx. 25 miles to the Mountain Springs Road exit. Exit south and take National Trails Highway west approx. 35 miles to Cadiz Road (Chambless, CA). Turn left on Cadiz Road and follow it approx. 4 miles to BLM Route NS376. Turn left onto NS376 and drive approx. 1 mile to BLM Route NS374. Turn left onto NS374 and drive approx. one half mile. The rock collecting area will be on both sides of the roadway.