39th ANNUAL SDSU GEOLOGY ALUMNI FIELD TRIP
Castle Dome Mine Museum
Yuma County, Arizona
Saturday and Sunday, March 14 & 15, 2026
SDSU GEOLOGY ALUMNI ASSOCIATION
The 39th annual SDSU Geology Alumni Association Field Trip will be the weekend of March 14 and 15, 2026. The primary geo-focused field excursion will be a visit to the Castle Dome Mine Museum in Yuma County, Arizona (castledomemuseum.org).
Several options are available at the Castle Dome Mine Museum and include a guided tour of the Hull Mine and its fluorescent mineral walls, a walking tour of the re-created mining town of Castle Dome City, and/or a guided tour of the many metal animal sculptures on the property.
Our group plans to join the Hull Mine tour that departs at 11am on Saturday, March 14. Please RSVP with me if you plan to join the Hull Mine tour at 11am. Our group can enjoy a bring-your-own lunch gathering in the parking lot after the tour(s). Depart mine about 230pm. Some will then adventure along the McPherson Pass Trail in the Kofa National Wildlife Refuge.
The Yuma Territorial Prison State Historic Park may be visited on Sunday (11am?) on the way back to southern California (azstateparks.com/yuma-territorial).
Alumni, faculty, staff, students, and guests with the Department of Earth and Environmental Sciences are welcome to attend. This is a great opportunity to get outside, look at rocks, and mingle with a bunch of cool folks.
COSTS
- The Castle Dome Mine Museum accepts CASH only for payment of its tours.
- Castle Dome City unguided walking tour fee: $20 ($7, 7-11yo)
- Metal Animal Sculptures guided tour (and ghost town) fee: $75 ($35, 7-11yo).
The Yuma Territorial Prison State Historic Park fee is $10 for adults ($7 for 7-13yo).
All costs are your responsibility. The SDSU-GAA will not pay for any camping, meals, motel, tours or any other costs associated with this weekend outing.
ACCOMMODATIONS
Several accommodation options are available. A dry camp will be set up on the road to the Castle Dome Mine Museum. Some attendees will be camped at the recently opened Yuma River Front KOA Journey (RV campground). There are also motels in Yuma.
DRY CAMP INFO
The flat, open dry camp site is accessible for vehicles with trailers, but low-clearance vehicles are not usually suitable on dirt roads. A portable toilet tent may be set up at the site (wind permitting). No facilities (water/electricity) are available at this location so be prepared for dry camping. Bring everything you need.
The planned campsite is located north of Yuma, along Castle Dome Mine Road at its intersection with McPherson Pass Road. From milepost 55 on US Highway 95 (between Yuma and Quartzsite), proceed northeasterly along Castle Dome Mine Road. The turnoff is about 29 miles north of Avenue 3E in Yuma and is marked with a sign “Kofa National Wildlife Refuge/Castle Dome.” The road is paved for about 3 miles then is a graded dirt road. At 7.3 miles from US 95, camp on the left side of the main dirt road near the intersection with McPherson Pass Road. There are some fire rings at this location.
Dry camp area — GPS 33.030108, -114.2025
COMMUNICATIONS
There may be unreliable or non-existent cell phone service at the dry camp and Castle Dome Mine Museum property. FRS channel 4 (no tone) will be monitored on Friday evening and Saturday morning, but FRS has a limited range. For the Amateur Radio Operators or “Hams”, National Simplex 146.520 will be monitored Friday evening and Saturday morning. Call for Sue-KM6HLY (other ham contacts will be updated closer to the field trip).
PLEASE RSVP BY MARCH 10 IF YOU WANT TO JOIN THE HULL MINE TOUR
ANY QUESTIONS?
Contact Sue Tanges, Interim SDSU Geology Alumni Field Trip Chairman
s.tanges@att.net, 619-922-9539
FOOTNOTES
The SDSU Geology Alumni Association appreciates this field trip suggestion offered by Greg Cranham.
Several geo-alumni visited the Castle Dome Mine Museum on February 28, 2025. The tour operators indicate that a new drift and fluorescent wall have been added to the Hull Mine tour this year.
The Kofa National Wildlife Refuge was established in 1939 for the protection of desert bighorn sheep and other native wildlife following a 1936 campaign by the Arizona Boy Scouts. Originally designated Kofa Game Range, the refuge was managed jointly by the U.S. Fish and Wildlife Service and the Bureau of Land Management for decades. In 1976, control of the refuge was awarded to the U.S. Fish & Wildlife Service, and it was renamed Kofa National Wildlife Refuge. The refuge’s name was derived from an acronym for one of the area’s most notable mines, the King of Arizona gold mine.