Charles Kuralt called this "the most beautiful drive in America. The pass is closed each year, generally from mid-May to mid-October, and it is already closed this year in early October. In the photo below (click to enlarge photos) you see the highway as it approaches the box canyon and is about to ascend in steep seemingly unending zigzag switchbacks taking you up well over 5000 feet. And yes, I did see bikers pedaling up both sides of the pass.
In the photo above, you see the entire box canyon. The highway takes you up and over the mountain on the left. If you enlarge the photo above, you'll see the edges of a few switchbacks in the shadows...
The above photos were taken from a lookout point near the top. There is plenty of parking, washrooms, and a path leading to a marvelous viewpoint.
At the top of the pass, you are far above tree line and have views like these of high mountain lakes below and mountain vistas in the distance. Snowstorms can even occur in the middle of summer, and high winds and thunderstorms are regular occurences.
In May of 2005, mudslides and rockslides in over a dozen locations covering 13 miles of road, damaged or destroyed and thereby closed the highway for the entire season. An estimated 100,000 cubic yards of rock had to be removed from just a half-mile section near the top of the switchbacks, and crews drilled down to solid bedrock to support the rebuilt roadway.
The 69 mile drive from Red Lodge to Cooke City takes over 2 hours, not counting whatever time you spend gawking from overlooks.