Montana Hodges - Rockhounding Northern California

Montana Hodges is a geologist and journalist who has traveled extensively throughout the West and wherever the rocks may take her. Her love for the natural world and affinity for writing led her to pen several FalconGuides, including Rockhounding Alaska and Rockhounding Montana. She was born and raised in California and continues to share her love of the Golden State as a geology professor at Northern Californias Sierra College.

F irst and foremost a grand thank you to all of my rockhounding companions who volunteered their time to circle Northern California on road trips that often tallied over two thousand miles. With the help of rock-hounds such as Tina Campbell, Cora-Lyne Bondi, Jessica McCartney, Taylor Grage, Gillian Sandusky, Adam Keele, Hansen Optenberg, Mariah Mendez, Carl Drake, Shawn Schiele, Tim Darnell, Diane Hodges, and Dr. Doom, we were able to put together a fully vetted site-by-site guide for the readers. This extensive guide offers easily accessible, legal, productive sites due to the suffrage of these adventurous rockhounds who braved severe weather, grueling hours, stuck cars, and flooded campsites all to explore the more often than not dead-end lead or less-than-worthy site. Thank you, friends!

Along with enthusiastic assistants, this book would not be possible without all the research of those who have fleshed out many of these locations over the decades and shared their knowledge, especially rockhounding and gold prospecting clubs. Many of these sites were also only possible with the help of rockhounds who readily and happily put aside what they were doing to show me the ropes, like Dennis Shirley and Ron Warnickthank you so much for your help! Yet the biggest thanks of all falls to fellow rockhounds, without whom life would be so dull. Lets see if we can teach one person this week how old Earth is, or what an ammonite was. Earth science education can only benefit this planet, and it sure helps if you get a prize at the end. Thanks, folks, for the like-minded attitudes and fire-opal spirits. I hope to see you on the rockhounding trails.

Land type: Mountains, tailings

GPS: N 3718'58.21" / W 11825'50.81"

Best season: Summer

Land manager: Inyo National Forest

Material: Garnets, quartz, chalcedony, calcite, diopside

Tools: Rock hammer, protective eyewear

Vehicle: High clearance, 4WD

Accommodations: Camping

Finding the site: This site is tricky to find and requires several turns on a crosshatch of dirt and gravel roads. Use your GPS and the coordinates for the best accuracy. From Bishop take 395 south approximately 2.5 miles and turn west onto Warm Springs Road. Drive 1.7 miles on the gravel road to the Stamp Mill (you can explore here for minerals in tailings as well). Stay right at the Stamp Mill and drive 0.2 mile on the powerline road; then turn left onto another unlabeled gravel road. Drive 0.4 mile, stay left, then another 0.1 mile. Turn right onto Forest Road 75166A and drive 0.1 mile to the exposure.

The view toward Bishop from the garnet site.

Sites 110

Rockhounding

This site might be tricky to find, but it is worth navigating the tangle of roads to collect beautiful garnet crystals, along with the occasional green or white diopside. Garnets are a silicate mineral, and due to their relative abundance and hardness (a 6.57.5 on the Mohs scale), they are often used as an abrasive. The gem-quality vitreous varieties are also used in lapidary arts and very popular gemstones in jewelry. The word garnet translates back to early English term for dark red. The pleasing colors of the garnets are distinctive, and this location offers easy collection of suitable specimens in cinnamon-brown color. The garnets here also tend to exhibit the classic dodecahedral (polyhe dral with 12 flashing faces) crystal structure.

A gem-quality Bishop garnet exhibits dodecahedral crystal habit.

This particular deposit is of grossular garnets, which tend to form in association with metamorphosed limestone, and you will see the light-colored eroding rock that has been cooked by Earth. Most occur in clusters within the beige baked limestone, but some shiny, small loose garnets can also be found by sifting the soil around the deposit. Mining was abundant in this part of the hills outside Bishop, and there are many other deposits to explore nearby. The old stamp mill also has some tailings around if you want to prospect for more minerals. The rock piles seem to be productive, but the area has been taken over as a local party and dumping location fruitful in anthropomorphic accumulations and graffiti art. Brave rockhounds can begin looking through piles around GPS N 3719'8.36" / W 11825'31.55" at the Stamp Mill where you make the first turn off Warm Springs Road.

Land type: Mountains, tailings

GPS: N 3721'29.88" / W 11816'43.21"

Best season: Summer

Land manager: Inyo National Forest

Material: Calcite, quartz, malachite, pyrite, limonite

Tools: None

Vehicle: High clearance, 4WD

Accommodations: Camping, RV parking, and motels in Bishop

Finding the site: From Bishop, be aware that the actual mine here is private along with some property around it, and, although it is abandoned, you want to stay outside private property lines. Explore around the hills and road for tailings.

Views from the Poleta Mine tailings.

Poleta Mine minerals.

Rockhounding

The Poleta Mine is an underground network of tunnels that date back to the late 19th century and operated until the 1960s. Thousands of ounces of gold and silver were extracted from the thousands of tons of ores here, and there was once an on-site stamp mill. Although it was long abandoned at the time of visit, the actual mine is private, and it is important to mind any trespassing signs. You dont want to enter the precarious shafts and tunnels anyway; they should be avoided. Stick to the many tailings strewn about the area. The metallic ores are associated with a quartz vein intruding the Cambrian (older than the dinosaurs by hundreds of millions of years) limestone of the area. You can find malachite drusy easily, chunks of quartz, the occasional quartz or calcite microcrystal pocket, and small limonite after pyrite cube pseudomorphs.

Land type: Mountains

GPS: N 3714'21.55" / W 11812'7.49"

Best season: Spring through fall

Land manager: Inyo National Forest

Material: Sulfur

Tools: None

Vehicle: