Gail,
The Big Horns are my primary camping site as they are just east of where I live. Highway 14 and 14a do have switchbacks and do have a few sections of 10 % grades (the signs say 10-14 miles of those grades, but it clearly isn't a uniform climb). However, there is a steady stream of RVs and trailers going over the mountains all summer long, meaning lots of successful ascents and descents. The roads are good and the speeds are pretty slow. I pull my 13'
Scamp up and down the steepest route (14a) with an old Isuzu Trooper with a small 4 cylinder and a manual transmission. I think the concept of the trip is more intimidating than the reality.
The primary problem I observe in others going uphill is simply overheating. Given how many units are on the road up and down, this is still not that common of an issue. Make sure you have got a well maintained cooling system. I pull my little unit up fairly slowly -- sometimes 20-25 mph in 3rd, 2nd, and sometimes in 1st gear. I keep my eye on my temperature gauge, but have never had problems. Even though this is a major route over the mountain, most drivers are very courteous and tolerant of those of us who creep up and down. There are enough pull outs to let others by if you need to.
Coming down the mountain is where I take extra care - coming down at about the same speed and in the same gears as going up. My nose tells me a lot of
brakes are being cooked by folks riding them the whole way down. My
Scamp does not have
brakes, so I take extra care and never let speeds get too high. Most of my braking is done by the engine.
Sibley Lake is a cute little lake created when a creek was dammed. Further west in the Big Horns you'll find smaller campgrounds and much dispersed camping. The forest opens with more meadows to the west also.
Sorry for the detail, Gail, if you are an experienced mountain tower. Enjoy your time in the Big Horns and elsewhere in the west. Feel free to ask if you have more questions about the area.
John