Yep, it is definitely a gravel road, a very long one. Generally in good condition in the fall, no steep grades, mostly long sweeping curves and no hairpins once you are on the old railroad grade, and very scenic when the aspen are changing.
Two other places I would suggest visiting while you are in the Cripple Creek area are the Phantom Canyon Road (but only in a TV or toad, not in an RV) and Florissant Fossil Beds National Monument. Like the Gold Camp Road, Phantom Canyon is an 1890's railroad grade, but, unlike Gold Camp, it is narrow gauge, not standard gauge. So, smaller radius curves, steeper grades, and narrower roadbed, ie., more exciting to drive! Florissant is little known to Colorado tourists, but worth spending half a day and maybe having lunch at their picnic area--as we did on an MG car club trip I led last fall.
If you would like to head southwest from Cripple Creek, but you don't have time or a suitable RV to take through Phantom Canyon, I have an alternative. Leave from Florissant and take the High Park Road to CO 9 and US 50. This "back road" (Teller Co. 1 to 11) is a good paved road, despite what some maps show, and more scenic than the alternative of US 24 to Buena Vista. The MG club drove High Park Road last fall and had a great time on it top down on a sunny, fall afternoon.
Have fun planning your trip and even more fun driving it!