The relationship between City of Rocks National Preserve and Castle Rocks State Park is still not clear to me as this campground appears on the National Park Service website, although it is an Idaho State Park. That said, the park rangers seem to work cooperatively. This campground is delightful. Located about a 7-mile drive/walk to the entrance of City of Rocks, Smoky Mountain Campground is situated above the valley providing a wonderful view from many sites including space #19 where I parked my campervan.  I believe the walking distance to the reserve could be shorter by taking any of the hiking trails from the campgrounds rather than going along the paved roads which first go away from the City of Rocks then back up again, making a big "U". 

During my one-night stay in February, water, showers and bathrooms in the campground were closed for the winter season. A very clean, pit toilet is located in the equestrian parking lot across from the campground entrance. The distance from the campsites to the bathroom will vary from quite close to about 1/4 mile max. And during the winter season, there won't be much competition for the spaces close to the bathroom, as I was the sole user during my time there. 

In addition to the breathtaking views, the sites offer privacy from 3 sides though all face the loop access road. There are picnic tables, fire rings and electrical power. I did not note if water was available as it would have been shut off in February in any event.  There is a dump station about 1 mile down the road toward the exit. I do not know if it is open in the winter.

Check-in during the off-season is accomplished by envelope collected at the entrance or directly to the ranger who came by in the morning to check-in. The rate was $27 per night. Definitely worth the money to stay in this tranquil campground so close to the magnificent City of Rocks.