As you're leaving Canon City driving towards the Gorge, there's a bend in the road just after the prison. Take a left into the large parking lot. Walk under the train tracks and upstream a bit and there should be a fun wave.
I haven't really surfed it since we had the good water a few years back, so it's possible things have changed. If I remember correctly it starts getting worthwhile over 2K. By 3.5K it was really fun. I doubt many people could do cartwheels or other verticle moves, but it was great for carving and flat spins.