We did Black Bear and Ophir this past July. Imogene was on our to do list, but my 40 year old Jeepster was really struggling at that altitude. That and the weather turned on us. The trails were pretty easy, aside from the altitude. Monerose has the more technical/crawling stuff. Some guys from our group did Engineer pass and said it was more difficult, but I wasnt there to say. One guy rolled on Engineer, but I was told it was from stupidity, not difficulty...This was one of our favorite trips ever!
Gorgeous country to explore. We stayed in Silverton for 5 days. If you go you MUST visit Animas Fork. it is a ghost town just a few miles from Silverton. There were several wooden homes still in tact, and remains of a few really cool mills.
Here is Black Bear Pass
And Animas Fork.