Information | Geology | SIU

Southern Illinois University



College of Science

students in field


Geology 454, our 6-week, 6-credit hour field geology course has been taught annually since 1970. We require this course of our B.S. degree candidates, and at the same time welcome applications from geology majors at other institutions. During most summers, about half of the class consists of students from colleges and universities across the nation. The instructional staff typically comprises from two to three full-time faculty members and one or two graduate Teaching Assistants. Course registration is normally limited to no more than 48 students.


The main goal of the field camp faculty is to teach people how to operate safely and efficiently as field geologists. We do a lot of instructing on the outcrop and conduct nine separate field exercises that range from one to five days in duration. Most projects include geological mapping and require the completion of one or more cross-sections.


The class spends about 60% of the summer at the Yellowstone-Bighorn Research Association (YBRA) field station near Red Lodge, Montana ( Its excellent permanent facilities include cabins, wash houses, study halls, and a lodge/dining room - home of outstanding family-style meals. We also work out of the University of Montana-Western (UM-W) at Dillon for seven days. Camping is limited to about 11 days during road trips.


View to the northwest along the Beartooth Front from the YBRA field station. The Lodge is in the distant foreground.

Why take a course in field geology?

Well, maybe your department, a grad school, or a future employer requires you to take one. If not, there are still good reasons to have a summer field course under your academic belt. Field geology offers students the opportunity to apply what has been learned in the classroom to real geological problems. Unless you already have fairly extensive field experience you should emerge from the course with a much deeper and more realistic appreciation of problems attending the collection, analysis, interpretation, and synthesis of geological information.

In the field, rocks look different than they do in textbooks or on lab benches. A valuable aspect of the field course is practice in approaching an outcrop and knowing what to do next. Even an incorrect solution to a field problem or a faulty interpretation of a geological event is of value because it prepares the way for a better solution or interpretation next time. As you get better at your job through practice, you gain confidence in your abilities. For this reason, a field course must stress individual effort and personal initiative. Students usually work in teams, primarily for safety, and we all realize that a good deal of learning can be derived from discussing ideas with classmates. But it is your own interpretation of the geology, developed from your own investigation, that will be of most value.

What are the prerequisites?

Participants must have completed courses in physical and historical geology, igneous and metamorphic petrology, structural geology, and stratigraphy. Course experience in sedimentology and geomorphology is recommended but not required. Most students take our field course between the third and fourth (junior and senior) years or during the final summer prior to graduation.

We work in - and see - a lot of great geology

From our Red Lodge and Dillon headquarters we map in Archean to Cenozoic material ranging from high-rank metasediments and ultramafics to marine and terrestrial sedimentary rocks. Map areas around Red Lodge best illustrate Laramide thick-skinned structural styles, whereas those around Dillon emphasize classic thin-skin tectonic style. We reconstruct Pleistocene glacial events from our own field maps, interpret stream capture sequences along the Beartooth Front, and apply first-hand observation to depositional problems in the Bighorn Basin. On a major excursion from Red Lodge, we travel through Yellowstone National Park, up the west side of the Sawtooth Mountains into Glacier National Park, and return to Red Lodge across the western edge of the northern plains.

Sun River

Sun River Canyon, Sawtooth Mountains, Montana. This area is characterized by thin-skinned thrust faulting and valley glaciation