Hmm. You're gonna have to find private land i think.
Theres this. Kinda canned but hey its a thing:
https://longmeadoweventcenter.com/
I know of public land north of Denver but not around cosprgs.
https://ndismaps.nrel.colostate.edu/indexM.html?app=HuntingAtlas
Spend some time zooming around on this, see if you can find something.
https://ndismaps.nrel.colostate.edu/indexM.html?app=HuntingAtlas