Come explore the West Desert of Millard County and the endless rockhounding opportunities.
Rules of the Trade
Collecting On BLM Lands
It is said that Millard County is one of the best locations in the world for rockhounding because of the variety of rocks, and exhilarating rare finds. From precious gems to ancient fossils, much can be found in our West Desert country. You never know what mysteries you will find underground.
With great desolation comes great hidden riches.
The casual rock hound or collector may take small amounts of fossils, gemstones and rocks from unrestricted federal lands in Utah without obtaining a special permit if for personal, non-commercial purposes. Petrified wood may be collected for non-commercial use only from public lands up to 25 pounds plus one piece of any size per day with a yearly limit of 250 pounds. Collection in large quantities or for commercial purposes require a permit, lease or license from the Bureau of Land Management.
Collecting On School Trust Lands
Most state lands are administered by the Schools and Institutional Trust Lands Administration. A rock hounding permit is required to collect on these lands. An annual permit if $10 per person or $200 per family. Up to 25 pounds per day plus one piece per person is allowed.
Agate Hill offers excellent agate in many colors. To get to the hill, drive northeast from Delta on US Hwy 6/50 to the Brush Wellman Road (about 11 miles). Follow that road west as if you were going to Topaz Mountain. When you have gone 31 miles you’ll come to a road that heads southwest. Follow it for about 3 miles, to where a dirt road forks south. Follow the dirt road for 1.4 miles to its end. Agate is scattered over the top of the large hill to the west.
Amasa (Am-uh-see) Basin
Visitors and locals alike work old abandoned mining claims for placer gold, and people actually find small quantities. The effort is mostly centered on old claims in the Amasa Valley, southwest of Marjum Canyon. Also found at the site are Albite, Biotite, Diopside, Garnet, Molybdenite, Gold, Pyrite, Quartz, Scheelite, Tourmaline, Tremo-lite, Vesuvianite, and Wollastonite.
Antelope Springs Trilobite
Denderite can be found in the Antelope Springs area. Oxide patterns color these rocks to make them look like plant fossils. Find then along a wash about 2 miles south of the U-Dig fossil site. From Delta go west on US Hwy 6/50 for about 32 miles to the signed road leading to U-Dig. Follow that road 17 miles to the Denderite site.
A solitary Lombardy poplar marks the old homestead at Antelope Springs. Along the main road going north of this tree is the abandoned site of the Antelope Springs Civilian Conservation Corps (CCC) camp established in the 1930s. The road will make a right turn to the left along the north edge of the camp. Follow the road up the mountain to get to Sinbad and more trilobite hunting areas.
Trilobite fossils are extremely popular with collectors. They are from an extinct group of arthropods that lived from the early Cambrian Period until near the end of the Permian Period. These hard-shelled prehistoric animals lived on the sea floors and reefs for millions of years. They developed into complex and beautiful animals, resulting in a variety of fossil-types.
The Antelope Springs area in Millard County is one of the best places on earth to find trilobite fossils. There are both public and private quarries, so make sure you know where you are. The private quarries are well marked. These private areas charge a fee to dig in their quarries, but can almost guarantee that you will find trilobites.
For the general location, see our rockhounding map. For more information on the private quarries, contact:
P.O. Box 1113
350 East 300 South
Delta, Utah 84624
(435) 864-4294 FAX
A New Dig
P.O. Box 122
Hinckley UT, 84635
Apache Tears (round nodules of obsidian) form if water is present during the cooling of obsidian lava. Curved, onion-like fractures may form. If the central core does not get hydrated, the fresh obsidian core ends up being an Apache Tear. Starting in Delta, follow US 6 north about 11 miles to the Brush Wellman Road. Turn west and travel 38 miles until you reach the Topaz Mountain sign. Drive pass the sign to the west end of the pavement. A gravel road will branch off of the main route to the left. Near this intersection Apache Tears can be found scattered on the surface of the ground.
Located on the Wah Wah Mountain Range, Crystal Peak is a result of a volcanic eruption from a nearby caldera around 35 million years ago. Nearly 1,000 feet of the Tunnel Spring Tuff is visible many miles away as its startling white color varies from that of the surrounding landscape. Quartz crystals and other rocks and minerals are embedded in the tuff. Pumice is present in the formation. Eroded holes in the face of the mountain attest to the forces of nature sculpting the peak by removing the softer pumice. Nearby in the Burbank Hills are Devonian to Permian carbonate rocks, named after Margie Burbank Clay, the wife of local Judge E. W. Clay. Fossils include fusulinacea (fossil shells which can have either one or multiple chambers, some quite elaborate) and stromatoporoids (fossilized sponges).
Desert and Keg Mountain, and Smelter Knoll
Rhyolite formations at Smelter Knoll offer pitted rock suitable for aquariums and flower pots. The remaining four places are located just above Millard County line in Juab County. Keg Mountain and Desert Mountain are composed chiefly of extrusive and intrusive igneous rocks of Tertiary age. Lacustrine and alluvial deposits of Quaternary age cover the older rocks and fill in the valleys. Topaz, pseudobrookite, specular hematite, and bixbyite occur in cavities in the Keg Mountains Rhyolite.
World-famous Fossil Mountain holds perhaps the most diverse accumulation of fossils in one area in the world. Early Ordovician fossil-bearing rock from six distinct rock formations roughly 485 to 470 million years old are to be found: the House Limestone, Fillmore Formation, Wah Wah Limestone, Juab Limestone, Kanosh Shale, and Lehman Limestone. Invertebrate fossil specimens to be found include: brachiopods, bryozoans, cephalopods, conodonts, corals, echinoderms, gastropods, graptolites, ostracods (bivalved crustacean), pelecypods, trilobites, and sponges.
Fossil Mountain is one of the better places in the Western US to find a variety of shells and other invertebrate fossils. On this mountain it is easy to find shale rock containing large numbers of fossils.
From Delta, drive southwest on US Hwy 6/50 for about 51 miles to the road leading south through Blind Valley. Follow that road southwest and then south for 12.5 miles to a spur which heads southwest to the north side of Fossil Mountain. From the turnoff you can clearly see the mountain. The spur road leads into a wash that defines the north edge of the mountain. Drive to the end of the spur road and then start looking for fossils in the wash and on the mountainside.
Deseret: Obsidian can be found west of Black Rock. Drive Hwy 257 south from Deseret for about 43 miles, until you come to a sign identifying a road that heads east.
Kanosh: Turn east onto the dirt road and travel about 6 miles to the sign for Black Spring. Turn right onto the Black Spring dirt road and park in the open area by the watering trough. Obsidian can be found all around that area. Most pieces are black but some reddish-brown and snowflake obsidian can be found.
Fillmore: Follow I-15 south to Exit 146 south to Kanosh. Cross the freeway to the east and turn south on the first frontage road. Travel south to a bridge crossing the freeway to the west. Follow this gravel road bearing west for approximately 26 miles. Or, take US 6&50 west of Delta to SR 257 and turn south. Travel about 43 miles, passing the Graymont lime plant, to the sign saying “Kanosh 26” (miles.) Turn east and travel on the dirt road 5.25-5.5 miles. In the depression, one road goes east, the other goes north. Mahogany, snowflake, and black obsidian can be found on the hillsides and on the roadbeds near Coyote Spring and Black Spring. Take the north road and then turn east at about ¼ mile on the first side road going east. Drive up the hill and over the crest.
A wide variety of rocks, minerals and fossils can be found in our West Desert country. See our rockhounding map for general locations.
Painter Springsarea offers garnets, pyrite, muscovite, quarts and other interesting rocks. It is located just northwest of Notch Peak. Follow US Hwy 6/50 west from Delta for about 54 miles to the Painter Springs Road. Follow it north about 12.89 miles to a spur road that goes east. Follow the spur for one mile to a fork where you stay left. Continue almost another mile to the end of the road. You’ll be in the mouth of a canyon, near the springs. Work the canyon bottom and foothills for specimens.
Agate can be found in many excellent colors at Agate Hill. To get to the hill, drive northeast from Delta on US Hwy 6/50 to the Brush Wellman Road (about 11 miles). Follow that road west as if you were going to Topaz Mountain. When you have gone 31 miles you’ll come to a road that heads southwest. Follow it for about 3 miles, to where a dirt road forks south. Follow the dirt road for 1.4 miles to its end. Agate is scattered over the top of the large hill to the west.
Coves along the east side of Topaz Mountain contain garnets. From the Weiss Road, drive north along the east side of the mountain for about 2.5 miles and look for the coves.
Apache tears can be found off the south west side of Topaz Mountain.
Obsidian can be found west of Black Rock. Drive Hwy 257 south from Deseret for about 43 miles, until you come to a sign identifying a road that heads east. To Kanosh. Turn east onto the dirt road and travel about 6 miles to the sign for Black Spring. Turn right onto the Black Spring dirt road and park in the open area by the watering trough. Obsidian can be found all around that area. Most pieces are black but some reddish-brown and snowflake obsidian can be found.
Denderite can be found in the Antelope Springs area. Oxide patterns color these rocks to make them look like plant fossils. Find then along a wash about 2 miles south of the U-Dig fossil site. (From Delta go west on US Hwy 6/50 for about 32 miles to the signed road leading to U-Dig. Follow that road 17 miles to the Denderite site.
People work old abandoned mining claims for placer gold, and people actually find small quantities. The effort is mostly centered on old claims in the Amasa Valley, southwest of Marjum Canyon.
Many other spots also offer good rockhounding opportunities. Inquire locally for ideas and directions.
Hunting and collecting sunstones glittering in the sun atop Sunstone Knoll is a great way to spend an afternoon, especially with kids. Some of the sunstones (golden labradorite) are the size of small fingernails. Others are larger and yellow in color.
Golden labradorite is believed to increase inner strength, vitality, courage, mental clarity, endurance and spiritual focus. The sunstones are easy to find on sunny days. Otherwise, dig where others have, and look for rocks holding the crystals within hollow cavities by cracking them open.
Sunstone Knoll is about 11 miles south of Deseret, just east of Hwy. 257. Turn left over the railroad track, then follow the road about one-quarter mile onto the knoll. See our rockhounding map.
The sunstone here is a transparent, yellowish labradorite (a plagioclase feldspar mineral) found as crystals in volcanic rocks and on the flats surrounding the knoll.
Topaz, Utah’s state gem, is a semiprecious gemstone that occurs as very hard, transparent crystals in a variety of colors. The topaz crystals at Topaz Mountain are naturally amber colored, but become colorless after exposure to sunlight. The crystals formed within cavities of the Topaz Mountain Rhyolite, a volcanic rock which erupted approximately six to seven million years ago (Tertiary Period) from volcanic vents along faults in the area.
How to get there: From Nephi, Utah, travel 33 miles southwest on State Highway 132 to Lynndyl. Turn south on U.S. Highway 6 and drive for approximately five miles. Turn west on the Brush Wellman road and travel 38 miles until you reach the Topaz Mountain sign. Turn north on the dirt road and drive about two miles, then turn west toward Topaz Mountain. See our rockhounding map.
- Utah highway map
- Lynndyl and Fish Springs 1:100,000-scale topographic maps
- Topaz Mountain East 7.5-minute topographic map
- The Bureau of Land Management (BLM) Recreation and Vehicle Guide to the House Range Resource Area map.
Topographic maps can be obtained from:
Natural Resources Map & Bookstore
1594 North Temple
Salt Lake City, UT 84114
801-537-3320 or 1-888-UTAH-MAP
Bureau of Land Management maps are available from:
BLM Utah Office
324 South State
Salt Lake City, UT 84114