Field Guide; Little Rocky Mountains part of MT Field Guides
This fieldtrip examines deformed Paleozoic sedimentary rocks on the margins of the Little Rocky Mountains, Tertiary intrusive rocks (porphyrys, magmatic-hydrothermal breccias, and dikes), and associated mineralization.

Yellowstone and Grand Teton National Parks and the Middle Rocky Mountains part of MT Field Guides
This trip is designed to show participants the granite-cored Laramide (Late Cretaceous-earliest Eocene) mountain ranges in the middle Rocky Mountains, and their various stages of burial by Cenozoic deposits and subsequent Quaternary exhumation. Mountain-flank structures involving Precambrian, Paleozoic, and Mesozoic rocks, the classic Heart Mountain detachment fault complex, and the rootless overthrust mountain ranges of the Wyoming-Utah-Idaho thrust belt are traversed.

Road Log to the Picket Pin Mountain, Chrome Mountain and Contact Mountain Areas part of MT Field Guides
This road log describes the geologic features along the access roads for three additional traverses: Guide to the Picket Pin Mountain Area, Guide to the Chrome Mountain Area, and A Traverse Through the Banded Series in the Contact Mountain Area. "This trip requires nearly 2 hours without stops. Beyond 12.5 miles, the road is rough and steep in places; a four-wheel-drive vehicle is recommended.

A Traverse Through the Banded Series in the Contact Mountain Area part of MT Field Guides
This traverse through the Banded Series of the Stillwater Complex follows the section described in detail by McCallum and others (1980)....Unusual or particularly interesting features are highlighted by the 22 localities along the traverse. In view of the nearly continuous outcrop, however, there is much of interest to see between localities, and full appreciation of the entire section would require several days. Nonetheless, most of the important rock types can be seen on a 1-day trip.

Plutonism at Deep Crustal Levels: The Idaho Batholith, Montana and Idaho part of MT Field Guides
The Idaho batholith field trip traverses a well exposed cross-section of the northern Idaho batholith, briefly examines the broad aspects of this deep-seated granitoid batholith and its regionally metamorphosed country rocks, and considers the role of the synplutonic mafic magmas from the mantle in providing heat for melting of continental crustal rocks to form the more felsic main-phase units of the batholith.

Geology of the Butte Mining District part of MT Field Guides
The Butte mining district is one of the major mining districts of the world with continuous production from both underground and open pit mines for 119 years, from 1864 to 1983. During this time, mining activites at Butte have introduced many firsts in mining methods, techniques of mine mapping, and the detailed recording of geologic data. This field guide describes the geology of the mineral deposits, provides a geologic map of the district, and concludes with a tour of eight locations of interest, including Alice pit, Syndicate pit, Berkeley pit, the Emma and Orphan Boy veins of the Anaconda system, the World Museum of Mining, and the Montana Tech Mineral Museum.

Early Proterozoic Geology of the Highland Mountains, Southwestern Montana, and Field Guide to the Basement Rocks that Compose the Highland Mountain Gneiss Dome part of MT Field Guides
The Highland Mountains are underlain by the largest of the northwesternmost exposures of basement crystalline rocks in southwestern Montana....Metasedimentary rocks in the Highland Mountains are in part lithologically similar to the Late Archean multilithologic sequence (in the Tobacco Root, Ruby, and the northern Madison and Gravelly Ranges), but are considerably thinner. In the Highland Mountains the individual beds of aluminous schist, marble, quartzite, and iron-formation extend for only short distances, but the assemblage as a whole is mappable. It nowhere exceeds 300 ft (100 m) in thickness and appears to pinch out to the north....these rocks in the Highlands, unlike those to the southeast, are overlain by more than 10,000 ft (3000 m) of aluminous biotite gneiss that may have been deposited as muds basinward from the Late Archean shelf edge.

Volcanism and Plutonism at Shallow Crustal Levels: The Elkhorn Mountains Volcanics and the Boulder Batholith, Southwestern Montana part of MT Field Guides
The Upper Cretaceous Elkhorn Mountains Volcanics (EMV) and Boulder batholith of southwestern Montana provide an example of a large-volume, epizonal, volcanic-plutonic complex whose deep level of erosion has exposed the cogenetic intrusive rocks while preserving sizeable portions of the volcanic field. Such a volcanic-plutonic association provides a unique opportunity for evaluation of many aspects of the evolution of a shallow-crustal magmatic system, such as geochemical relations of both the volcanic and plutonic rocks and the nature of intrusive-extrusive relationships at the present level of exposure.

Field Guide; Belt Butte and Tiger Butte part of MT Field Guides
This field trip extends east from Great Falls across rolling glacial plains to the summit of Belt Butte, where its formation and the collapse structure adjacent to it will be discussed. In addition, the Tiger Butte laccolithic intrusion, contact metamorphic effects, associated dikes, and structure resulting from the intrusion will be examined.

Road Log from Bozeman to Specimen Creek via Gallatin Canyon and U.S. 191 part of MT Field Guides
This trip leads southward through the Gallatin Range to Specimen Creek in Yellowstone National Park. It affords an excellent worm's-eye view of the structure and stratigraphy of this range as revealed both laterally and vertically through the quietly beautiful Gallatin Canyon. The route also borders the east margin of the Madison Range and its spectacular Spanish Peaks uplift. The Gallatin and Madison Ranges are geologically and topographically similar, an essential difference being the thick cap of andesitic lava and breccia that covers the high parts of the Gallatin Range.