The first site we visited (let's call it Site 1, since imagination is precious and should be conserved) was an exposure of the famous John Day Formation, which has yielded one of the largest and best-preserved Oligocene faunas in the world. Since the primary purpose of our trip was to teach basic paleontological field methods, the bulk of our time was devoted to creating stratigraphic sections for the outcrop. There was, however, time for fossil prospecting as well, and it was very - almost ludicrously - productive. Among the things we uncovered were rodents (particularly squirrels and aplodontids), hypertragulids (mouse deer), canids, nimravids (sabertoothed, cat-like carnivores), horses, entelodonts (bearlike relatives of pigs), and rhinos. Perhaps the most impressive specimens we unearthed were four skulls of oreodonts, pig- and/or sheep-like ungulates that were abundant in the late Oligocene of Oregon (we found ample oreodont postcrania as well, some of which are pictured above).
Our second site (being creative once again, let's call it Site 2) was less fossiliferous but scientifically much more interesting. Instead of just getting a handle on the local stratigraphy as we'd done at Site 1, we were also interested in pinning down the age and paleoenvironment of Site 2, both of which were big question marks going in to field camp. Fortunately, the fossils we found were exactly the ones we'd hoped for to be able to assign an age to the fauna: jaws of the canids Tephrocyon and Cynarctoides, teeth of the horses Archaeohippus and Merychippus, the beaver Monosaulax, and a smattering of camels and paleomerycids (antelope-like ungulates). For those of you who know your North American biostratigraphy, that places you unequivocally in the mid-Miocene (~16 Ma), which in this part of Oregon means you're in the Mascall Formation. Pinning down the paleoenvironment was made easy by the discovery of a bird (probably some kind of waterfowl) and by several shell fragments of pond turtles (I won't insult your intelligence by telling you exactly what the students concluded about the site's paleoecology, but if you can't figure out what environment is likely to be represented by waterfowl and pond turtles, I question whether this is the blog for you).
So there you have it: for a trip whose primary motivation was teaching, we had a remarkably successful couple of weeks in the field (and not just in terms of finding fossils; we were very lucky weather-wise as well, though the last couple of days did manage to break the 100° mark). We and our specimens are now all safely back in Eugene, with the latter awaiting curation and, eventually, a trip back east, where they will be reposited in the collections of John Day Fossil Beds National Monument.