We are going on vacation to Keystone SD.   I have always wanted to ride to enjoy the landscape.   Any recommendations on trail rides (stables or ranch) where you really ride (steep trails, crossing water, etc.) that aren't "kiddy" rides?  If I could find unguided, that would really be awesome.   

Trails all over up there.  You can go to Bluebell Horse camp at Custer State Park and there are numerous trails, all self guided.  Trust me, you will cross the creek dozens of times, till you get tired of it!  You can ride up to Harney Peak, now renamed Black Elk Peak.  Check out this website, it will help a lot.  http://www. fs.usda.gov/recarea/blackhills/recreation

Thank you!!!