We were at Jellystone in Larkspur. They have all types of sites there, elect only, elect/water, and full hookups. Park is more "natural" than most RV parks. It's on a hillside with gravel roads and scrub oak/conifer trees between the sites. You may want to do a couple weeks of stairmaster before going here if you plan on hiking around the camp though. Very nice park hosts there. The baby nubian goats are being bottle fed by the park managers family for the next few weeks. If you are camping there, you can help bottle feed them. If not, they do charge a small fee (and people were coming in from all over to do so.) My daughter and wife got a kick out of doing this and didn't miss too many feedings. We did not get into Larkspur proper, but did spend some time in Castle Rock old town area. Found a really nice little restaurant there called the Pegasus. We'll be going back to that place even if we aren't camping.
Dakota Ridge is up in Golden. Look it up in RVParkReviews.com. They are associated with the same company that runs the place we stayed at last fall up in Estes Park. Fall in Estes Park in wonderful with the bull Elk down in town bugling up a mate or three. Lots in Estes Park are much closer together here in a more commercial camping setting. But for us, camping is just a place to basecamp out of, while we explore the local areas.
If you are looking for more rural boondocking areas, look around Buena Vista area. I've got friends that make an annual trip up there each summer to ride the dirtbike/ATV trails in that area. We usually take gensets up there to run in the evening to recharge the campers batteries. There aren't any camping neighbor to bother there, except maybe some deer and coyotes.
2008 Toy Tundra DC 5.7L Bagged w/LTs
2012 Windjammer 3001W, Atriumed