Search for campgrounds around Lake Dillon, there are several. I dont know, but would expect those campgrounds to on a USFS reservation system, and would highly recommend reservations. Lake Dillon is busy in July, and just an hour from a billion people in the Denver metro area.
It is a beautiful area, and there will be lots to see and do besides the ceremonies you are attending. I don't camp there myself, since I am not a big lake boater. Enjoy!
Lance 995 TC, Ford F250 4WD, camper pkg, stable loads.