There's a shooting area out by Bailey. Doesn't take too long to get there from Denver.
Head out 285 toward Bailey. Just before you get to Bailey, there is a light where Co Rd 43A "T's" into 285. There's a gas station there ahead and to the right. Turn right at the light and follow Deer Creek Rd for approx. 6.7 miles where the road will "Y" with Deer Creek Rd going left and Co Rd 47/Clark Rd going right. Take Clark Rd to the right. Stay on the main paved road. (it will change names a couple of times) You'll end up being on Shelton Dr. Come to the intersection of Shelton and Neal Rd. Across and to the right there will be a building with a red tin roof. Take a right on Neal and there will be a pond directly besides the road on your left. Take a left right after the pond on Pike Nat. Forest Rd. 108. Follow this road through the woods till you come to a "Y", stay to the left. Continue until the road makes a hard "90" to the left and immediately "T's" into another dirt road. Take a right. You'll drive out through an open meadow and then back into some trees again where there is a turn off to your left. Take this to the left and you'll be at the shooting range.
It can be a little messy as most people don't clean up after themselves.
But it's a safe place to shoot.
Also, if you go back out to where Deer Creek Rd and Clark Rd "Y" and continue down Deer Creek Rd all the way to the very end, there's a parking area and the trailhead to Mt. Rosalie.
Now, if you're looking for a good place to bounce around in the Cruiser and have a picnic, there's Slaughter Gulch out there as well. (You can't shoot there though)
To get there, go back out on Deer Creek Rd, and back just before it "Y"'s with Clark Rd, there's a road called Saddlestring Rd. Drive down this road a short piece and it will make a "90" to the left and then there's the entrance road to Slaughter Gulch on the right.