Here are my two nominees for the Liquid-Based Darwin Awards. Neither of these occurred on CC, but still on the Front Range, so hopefully close enough.
1. This happened in 2004 on the Poudre. I was coming back down the canyon one night to see two guys on the side of the road at the big diversion below BTO. This is a nasty low-head dam with a bunch of stuff at the bottom of it. One of the guys is in his boxers with a tube in one hand and a beer in the other. The river's running about 3.5, so a pretty decent level. The guy in his boxers proceeds to wade out into the middle of the river in his boxers with innertube and beer in hand, hop into the tube, and go over the low head dam. I thought he would get munched at the base of it, but he paused for about a half second, then floated right through. He waded out, hi-fived his brah, then headed back up to run it again. I didn't stay for the second one, but didn't read about him in the paper.
2. THis happened last year at the A-Hole in Lyons. I was there playing at the A-Hole on a Friday afternoon. It was pretty hot. Early July maybe? There were a few on-lookers there, one of which was pretty lit. He has a couple of kids with him. Don't recall any spouses or s/o's, but they may have been in attendance. I had just climbed out of the boat to pack up and head home, when I see this dumby standing on the rail of the footbridge over the river right below the hole. He proceeds to jump off the bridge into the pool downstream of the hole. No idea how deep the water is there, but the flow was pretty low. Next, he jumps in upstream of the hole, swims downstream into the hole head first, and climbs onto the bank of the river unscathed.
No embellishment on either of those. None needed!!