Bedrock geologic map of the Castle Reef Quadrangle, Teton and Lewis and Clark Counties, Montana
M.R. Mudge 1968 U.S. Geological Survey, Geologic Quadrangle Map GQ-711
This 7 1/2 minute quadrangle is located in northwestern Montana. Mississippian carbonates overlain by Jurassic siltstones and sandstones are folded rocks and cut by numerous thrust faults that exhibit classic thrust relationships. Robert Burger writes: 'This is the final map in the series of three I use in my structure course for student-constructed cross sections and is the most difficult, but it is manageable by the end of the course. Once again I scan the line of section at 300 dpi and at an enlargement of 200%, which gives students more room in which to work. Difficulty level for map interpretation: moderate to somewhat difficult; difficulty level for student-constructed cross sections: difficult.'