Flat Irons marking the Bitterroot Detachment surface (Jeff Lonn)

Join us for the 45th Annual TRGS Field Conference in Hamilton, MT on July 23-26!

Join us for the 2020 TRGS Field Conference in Hamilton, MT this coming July. We welcome proposals for field trips, posters, and papers about any aspect of the geology in and around the Bitterroot Valley. Field guides, abstracts, and papers will be published in Northwest Geology, the annual publication of TRGS. Please contact Jeff Lonn (jlonn@mtech.edu) by March 15, 2020 with your proposed titles. Submission guidelines are posted at here. All manuscripts and road logs must be received by April 15, 2020.


The Bitterroot Valley records over a billion years of sedimentation and deformation. Geologic topics of interest include Proterozoic basement rocks, the Mesoproterozoic Belt Supergroup, Mesozoic batholiths and major thrust faults, the Eocene Bitterroot metamorphic core complex, and Miocene to present high angle normal faults. The Bitterroot Valley contains Quaternary glacial features and pediments, and preserves shorelines associated with Glacial Lake Missoula. Some of these features are cut by Quaternary fault scarps associated with modern extension.


Local mineral resource localities include the lead-silver veins tapped at the Curlew mine (near Stevensville), rare earth mineral occurrences, and the recreational mining of sapphires in the alluvium along the West Fork of Rock Creek in the Sapphire Mountains.


Want to help with the conference? Contact Jeff Lonn at jlonn@mtech.edu

Locations of Past TRGS Field Conferences

2019 Deer Lodge, MT

2018 Bozeman, MT

2017 Leadore, ID
2016 Heise, ID
2015 Elliston, MT
2014 Republic, WA
2013 Salmon, ID
2012 West Yellowstone, MT
2011 Superior, MT
2010 Anaconda, MT
2009 Philipsburg, MT
2008 Red Lodge, MT
2007 Dillon, MT
2006 Libby, MT
2005 Sun River-Choteau, MT
2004 White Sulphur Springs, MT
2003 Missoula, MT-Salmon, ID
2002 Virginia City, MT
2001 Wallace, ID
2000 Butte, MT
1999 Lewistown, MT
1998 Lincoln, MT
1997 Livingston, MT
1996 Twin Falls, ID
1995 Dillon, MT
1994 Cranbrook, BC
1993 Indiana Univ. Geologic Field Station, MT
1992 Red Lodge, MT
1991 Great Falls, MT
1990 Salmon, ID
1989 Dillon, MT
1988 Missoula, MT
1987 Helena, MT
1986 Moscow, ID
1985 Bozeman, MT
1984 Boise, ID
1983 Kalispell/Whitefish, MT
1982 Dillon, MT
1981 Pocatello, ID
1980 Spokane, WA
1979 Anaconda, MT
1978 Missoula, MT
1977 Anaconda, MT
1976 Bozeman, MT

© 2016 TOBACCO ROOT GEOLOGICAL SOCIETY - Butte, Montana    |    A 501(c)3 non-profit organization