There are several areas south of Buffalo Creek, the one you mentioned among them. It is short, maybe 40-50 yards max. It gets real busy on the weekends. Another short range is a couple of hundred yards south, on the right side of the road, and back about 100 yards. Not enough room for too many to shoot at the same time, though.
A favorite place to go in that area is over by Harris Park. Last I heard, though, it was still closed for fuel woods mitigation. Correction, the land is open, if you want to carry your gear about a mile back to the range that people have been using for 30+ years. The ranger I talked with didn't have any idea when the area would reopen to motorized vehicles. It's a nice area, with hills on the north and south sides. I have seen as many as 12 or 15 groups there shooting at the same time. Lots of room. Up to about 500 yards if you're there by yourself. Every year, for the last 6 or so that I have following it, there seems to be at least 1 area that has been used for some time is lost through USFS closure, usually without notice. When Slaughterhouse Gulch was closed, it was an "Emergency" closure, signed by a judge in Pueblo. I have heard he is one of the USFS's favorites for anti-gun issues. I also know Roy Romer's daughter's family owns a bunch of land in that area. Care to guess the connection?
Slaughterhouse Gulch, Slot Canyon, the dump by Bailey, Allenspark, Rampart range road range, were all popular areas that have been closed in the last 5 years. Harris Park and Lefthand Canyon are both "temporary" closures, but for how long, no seems to want to give an answer. Maybe we should follow the heard, and head to Cherry Creek. moooo