Steven Schweitzer's "A Fly Fishing Guide to Rocky Mountain National Park" will be an excellent resource for you. Best darn fishing guidebook I've ever read. Tells you what waters have what trout types and has elevation charts for all trails to them. Marty Bartholomew's "Fly Fishing Guide to Colorado" is also an excellent resource and one worth your time if you plan to spend that much time in this state.

Kremmling is an interesting potential base point, with good access to a lot of good waters. The Allington Inn & suites is a fine place to stay there.

Enjoy!