Abstract Lower Cambrian–Lower Ordovician passive-margin sediments were deposited across northeastern Washington, northern Idaho, and western Montana. Lower Cambrian strata record the initial transgression onto Laurentia in northeastern Washington. Middle Cambrian–Lower Ordovician units were deposited across a much broader area and record the establishment of a western ooid-algal shoal complex that restricted water circulation in an intrashelf basin that formed between the shoal and craton. Long-standing topographic highs in the region include Montania, which may have controlled the location of the ooid-algal shoal complex, and the Lemhi arch, which served as a western source area for siliciclastic sediment input. The Sauk megasequence sediments were deposited in multiple grand cycles that are regionally correlative. Each grand cycle consists of a shale and sandstone base deposited as sea level transgressed onto the craton. The basal siliciclastic units are gradationally overlain by carbonate, which was deposited as sea level continued to rise and an extensive carbonate platform developed. Some of the boundaries between the grand cycles are unconformities, recording rapid changes in sea level. Meter-scale shallowing-upward cycles are common within grand cycles, but they have not yet been regionally correlated.

The Yellowstone-Bighorn Research Association (YBRA) is a nonprofit research and teaching organization chartered in the state of Montana in 1936. YBRA maintains a field station south of Red Lodge, Montana, at the foot of the Beartooth Mountains at the NW corner of the Bighorn Basin. The YBRA Field Station has been host to a wide variety of primarily geological field courses and research exercises, including a YBRA-sponsored Summer Course in Geologic Field Methods , offered initially by Princeton University and subsequently by the University of Pennsylvania and the University of Houston. Enrollments in that course vary from year to year, an experience shared by other field-course programs. The YBRA field station does not depend exclusively on field-course enrollment; by diversifying its client base, YBRA has been able to operate effectively through high-amplitude variations in enrollment in traditional courses in field geology.

At the University of Montana Western (UMW), geoscience classes are taught primarily through immersion in field research projects. This paper briefly describes: (1) why and how we achieved a schedule that supports immersion learning, (2) examples of two geoscience classes taught in the field, (3) assessment, and (4) the challenges of this model of teaching and learning. The University of Montana Western is the first public four-year campus to adopt immersion learning based on one-class-at-a-time scheduling. We call it “Experience One” because classes emphasize experiential learning and students take only one class for 18 instructional days. The system was adopted campus wide in the fall of 2005 after a successful pilot program funded by the U.S. Department of Education. The geoscience curriculum has been altered to reduce lecture and focus on field projects that provide direct experience with the salient concepts in the discipline. Students use primary literature more than textbooks, and assessment emphasizes the quality of their projects and presentations. Many projects are collaborative with land-management agencies and private entities and require students to use their field data to make management decisions. Assessment shows that the immersion-learning model improves educational quality. For example, the 2008 National Survey of Student Engagement (NSSE) showed that UMW has high mean scores compared to other campuses participating in the survey. Of the many challenges, none is more important than the need for faculty to change the ways in which they interact with students.