I am writing this to ensure people know the Upper Animas is a hardcore, awesome whitewater rafting experience. My best one-day whitewater trip ever. However, it is NOT for the new-to-whitewater-crowd. The Lower Animas that runs through town is mellow and fun for families.
Now back to the Upper. You ride the train to the middle of nowhere, unload your gear, don wetsuits and buckle in for one of the wildest rivers available in the Lower 48. It's just an incredible experience, wilderness and some of the gnarliest whitewater you can hire a guide service for! Great fun.