Camp Slanty (Site #A30) This is a pretty nice campground outside of Estes Park that we reserved on Reserve America because it is only 55 minutes from the office. We pulled in, black full and half a fresh to a fully packed campground just outside the entrance to Rocky Mountain National Park. The road was certainly narrow and as Tiffany and I were parking it around the 70 degree bend in front of our site, the transmission temperature light came on.