Duration: 7 days

Leaders: Doug Kreiner and Erin Marsh

Dates: July 27 – August 2, 2025

Start: Fairbanks, Alaska

End: Anchorage, Alaska

Beginning in Fairbanks and ending in Anchorage, this trip will include Fort Knox, Livengood, Shorty Creek, Pogo, Manh Choh, and the Valdez Creek placer. It will also highlight the critical minerals work that has been done in the upland and supported by the USGS Earth Mapping Resources Initiative. Lastly, it would provide an overview of a number of different deposit types: 1) Paleocene porphyry Au(-Cu) (Shorty Creek), 2) Cretaceous intrusion related Au (Fort Knox, Livengood/Money Knob), 3) quartz-hosted Au (Pogo), 4) Late Cretaceous skarn Au related to a porphyry (Manh Choh), and 5) Placer Au related to orogenic Au veins at Valdez Creek.

Duration: 5 days

Leaders: Eric Anderson, John Dilles, Kyle Eastman, Mark Reed, Chris Gammons, Karen Lund, Kaleb Scarberry

Dates: July 29 – August 3 

Start: Bozeman, Montana

End: Bozeman, Montana

The world-class deposits of the Butte mining district, Montana have a long history of production leading to the area being referred to as the “Richest Hill on Earth.” The deep porphyry Cu-Mo deposits are overlain by shallow Cu-rich (Au-Ag-Pb-Mn-Zn bearing) zoned lode deposits
hosted in the Butte granite phase of the Boulder batholith. This 5-day field trip will explore the geology and mineral deposits that occur within and around the Boulder batholith. We will visit underground and open pit workings and observe mineralization and alteration in historic deep drill holes of the Butte district. This trip will compare the Butte mining district to other types of deposits associated with  the batholith including skarn, carbonate replacement, stockwork, and lode vein deposits. In addition, we will discuss environmental issues associated with historical mining, and provide updates on current research and future directions for critical commodity production

Duration: 1 day

Leaders: Richard Pilco (Mine geologist) and others to be determined

Date: August 8, 2025

Start: Golden, Colorado

End: Golden, Colorado

*Note: High elevation (>2.5km above sea level)

This trip will include an overview of the active mining area and deposit discussion with mine geologists at the core shed. Cripple Creek is a world class alkalic epithermal deposit and has produced more than 20 million ounces of gold (historical and modern production) from a diatreme complex. The Oligocene-aged volcanism hosts vein and disseminated-style mineralization extending to depths of more than 1,000 m from present-day surface.

Duration: 5 days

Leaders:Douglas Yager, Mario Guzman, M. Steven Enders, Mary Doherty

Dates: August 8- 12, 2025

Start: Golden, Colorado

End: Golden, Colorado

*Note: High elevation (>3km above sea level);                              overnight stay at 2800m elevation

This trip will explore mineral deposits of the  San Juan volcanic field.  The volcanics and intrusives in this field cover an area of approximately 25,000 km2. The trip will include visits to several super volcanoes (volcano explosivity index of 8) and caldera-hosted mineral deposits. Mineral districts visited include: Creede, (Ag-Au-base metal, Intermediate Sulfidation (IS) epithermal vein); Summitville, (Au-Cu-Ag, High Sulfidation (HS) epithermal); Silverton, (Pb-Cu-Ag, HS epithermal; Cu-Mo porphyry; and Ag-Au-Cu-Pb-Zn-Cd, IS epithermal vein), and Ouray, (Ag-Au-base metal, IS epithermal vein).   We will have the opportunity to compare and contrast the volcanology, mineral deposits, alteration systems, mining districts and environmental stewardship for this remarkable and scenic region that will make for a fascinating trip.