here is the most important info you should know about-
Clear creek has fish, and a decent amount of them. Mostly you wont find anything above 8-10 inches but sometimes you will. The further upstream you go the smaller the average size. *mostly*. It fishes like the Poudre- you have to look for deep cuts after a good bend, they always seem to be right between the run and the riffle.
Because it is predominately Browns and Cut-bows, you will have a better time from spring into fall than any other time of year.
This also means that you have to be wary of the Yuppie raft and kiaker clans that migrate all summer long from the casino to the lower tunnel.
The creek is not all that big for a boat and a fisherman to share the river so it can be frustrating.
Also be advised that Black Hawk recently demolished some building(s) and that area might not be a great place for some time. Idaho Springs will yield a longer stretch with less people on it but it is a demanding hike up and down banks to and from your vehicle.
Physically frustrating, yet the reward can sometimes be well worth the effort in my opinion.