Public pay as you go outdoor range over in Cherry Creek. When I lived in CO, was a member of the Ben Lomond Gun Club. Range is just East of Kiowa. Reasonable dues, 8 hr per year work committment (cleaning range, nailing up target holders, policing brass) It is a bit out of the way, but it IS a 500 acre+ range- room to shoot anything short of artillery. Link for ya- BLGC Home Page
PS- you need to be member NRA.