I hate to say this but the Broomfield area is surrounded by private property, there really is no area to shoot outside of a range, public or private, unless you know someone in the area with lots of land and who will give you permission to shoot. I lived on a farm in the Del Camino exit area as a kid in the 60's and even back then it was starting to get hard to find somewhere to shoot informally. Up in the mountains it's a little easier to find open land to shoot on however. The front range has grow so much in the last 35 years as to make it almost unrecognizable.