You've got an excellent, excellent point. I think there should be fish cleaning stations at all parks that require a fee to use them. If they're going to charge us a fee to fish or use ElevenMile, why shouldn't they have a fish cleaning station, complete with running water and trash cans? I know, for those of us that take the fish home, we could do without. But, for the campers or those who like a shore lunch of fresh fish, what can they do?
Myself? If I'm fishing with my boat, the boss and I use the livewell to keep them alive during the trip. Before the ANS issue, I'd just leave the fish in the livewell and they'd still be alive when I got home. Now, you're supposed to drain the livewell, so we do that and bag the fish on ice in a cooler (I need a really, really big one!) for the trip home.
Some lakes, like Ridgway and Blue Mesa, have cleaning stations. I will generally use them lakeside. Good place to meet and greet other anglers and talk about the day's events.
When I'm walking and wading, its a lot harder to take care of the fish. I generally release all of those fish. If I kill a fish, though, I'll pack it in moist, green grasses and try to get it back to my truck ASAP.