I have driven and ridden it several times. It is quite scenic, on the north end your riding in the flat land then jump up into the mountains your kinda riding along the Rockies. I have not been on it since 2015, at that time the pavement was getting chewed up here and there. There is forestry road access off of it so you can encounter muddy sections where the heavy rigs enter the road. The only services I recall would be at Grande Cache. Gas, food and Lodging are available.
We might be riding it in early June If I do I will post up an update for you.
Update on the Bighorn Highway. I did not ride it in my June or July trips this year but I just drove yesterday it in my pickup. Overall it was in good shape but the southern end had the road pretty chewed up with pot holes. A lot of the road had fresh pavement and they where working on areas in the northern half they seemed to be adding some passing lanes. It will be great when they finish.