Glenwood Springs is a tourist type of town. What a journey on I-70 to get here from Denver. Speed limits change often (as low as 40 MPH) due to sharp curves. It took 20 years to complete the interstate from Denver to Glenwood Springs. When you drive it, you will see why.
The Colorado River runs right through town. The river is at the base of the mountains. A railroad track is carved into the mountain just above the base and maybe 100 feet above the river. What a ride and sight that must be from the train's perspective.
White water rafting is available at the Rock Gardens. It is at exit 119 (the exit is called "No Name" because it really goes nowhere). The first rides begin at 9:00 am. They want you there by 8:15 am for fitting of gear plus the state-required safety spiel. They will tell you what to do if you or anyone falls out of the raft. A half-day run costs about $50. A full-day run is about $80.
The raft is loaded on a trailer pulled by a van. Depending on the size of the group, you ride either in the van or on a school bus. The van/bus takes you several miles up stream to a ramp. You help carry the raft to the river's edge.
A guide takes anywhere from 3 to 8 people on a raft. The guide does most of the work while on the river. You do paddle when going through a rapid (and you will get wet, especially at the front of the raft).
To dress for the raft trip, AVOID COTTON, including socks and underclothing. Rock Gardens will lend you a pair of rubber shoes (no socks). Wear sunglasses and sunscreen. Dress in layers too as you will warm up quickly. Not much you can do about your hands unless you want to wear rubber gloves. You might want to wear a hat but if you fall overboard, the hat may be lost.
While in the raft, there is no place to hold on. You have an oar in both hands anyway. Sit on the side of the raft and wedge your feet between the seat you are on and the one behind you. Keep your center of gravity as low as possible.
Category 3 is the typical run. Pretty easy to handle. Usually no one falls out. For a category 4 or 5, the water must be rushing pretty good (4000-plus is some number they use). This kind of water is available usually only during May and June.