Last summer I drove out to Bozeman, Wyoming for a GIS conference and took a rather circuitous route both outward from and back into Vermont. We decided to camp at Buffalo Bill State Park along the reservoir and then return to Cody after setting everything up. On our way back into Cody, just before the famous rodeo stadium, the setting sun illuminated this fantastic angular unconformity exposed in the Shoshone River. Based solely on the descriptions found in Torres and Gingerich (1983) I think the lower reddish unit is the Eocene Wildwood Formation overlain by the volcaniclastic Aycross Formation. I haven't done any work at all, so this is solely based on reading geologic descriptions, hope I'm close.
View Angular Unconformity in a larger map