Re: Interesting Alpine Fish
They resemble Dolly varden (white spot char) in a post juvenile stage of growth. I don't think there are bull trout in CO. and I wouldn't know why even a state department of F&G would introduce Lake Trout into streams like you have pictured.
Likewise, I am not sure of the existence of Dolly varden in your area but I've caught quite a bunch of them and your fish look similar to young char. Most especially the first 2 pictures of them. I believe the way to solve the issue would be to e-mail attached pictures to your regional biologist there. I have developed good rapport with my state biologists from Skwentna to Kodiak, it's a big help in many ways.