Congrats!
You have here listed some of the best trails in the whole region, ones that I explored for years while down in Durango. I used to drive Hummer tours on those trails too.
Stony Pass is amazing, with several steep rocky sections and river crossings. I suggest you go from Silverton to Lake City via Stony Pass. There is a great place to camp at the top of Stony Pass (12,800+ feet!) just a little ways over the top on the Lake City side.
I would return to Silverton via Cinnamon Pass, and keep in mind that while the map only says it's 30 or so miles each way, it may take a full day to do that. Stony is very rocky in spots so you can't go very fast.
Clear Lake is a good warm-up (easiest trail listed) and is a short day trip from Silverton. There are large Brook Tout in that lake too so it makes a good Cruiser-accessed fishing spot.
There is great mine viewing on the Alpine Loop and other trails that connect to it. I would suggest California Pass (from Silverton via Animas Forks), which has a very huge Mine Mill and other places to explore. There are still mine tram towers along California as well as Stony Passes. Animas Forks has roughly 20 ghost town buildings present and is a great spot to explore.
Yankee Boy Basin is recommended and gets hairy in spots (also a good warm-up for Imogene). It is a dead end, and very popular, although there are a few camping spots this is one of the more popular spots iin the region and may not have a camping spot available. The geology is very interesting in this basin. Also lots of mines in the area, but they are on private land instead of BLM land so you can't really explore them at all.
Imogene is the most technical pass that I have done in the area. Black Bear is worse/better, but was told by people that have done it that a stock vehicle WILL NOT make it, and the reason that the trail is one-way on the downhill side into Telluride is that there are several shelf spots that drop 3 feet or 4 feet, and there are the 20 or so switchbacks that someone drives off of (3-point turns at every switchback) and dies pretty much at least once every year.
Now Imogene is AMAZING and a great feeling to take a Toyota up to 13,100+ feet!!! I took my 1984 Hilux to the top and it is unreal up there. You will enjoy it. I went from Ouray to Telluride, and there are some long steep climbs (one of bedrock granite) on the Silverton side. I "hit the 3 wheel motion" on that trail with the straight front axle a bunch of times. Expect to do some 3 wheeling if you have a straight front axle.
Both Black Bear and Imogene SHOULD be open at that time, but be sure to call the BLM or Forest Service to find out because sometimes they don't open at all due to snow or becaus the "roads" (term is used loosely with these two trails in spots) are washed out by the run-off. Alta Lakes is also a fantastic place to camp and there are cutthroat in the lakes there.
Ophir is a steep climb from the Telluride side to Silverton and is only 4-wheel to the top at 12,800 feet. There will be one uphill 3-point turn on this pass. From the top, it is a narrow 2 wheel drive road on the Silverton side. It is one of the easiest trails in the region, but a must do for the view.
Have fun, be safe, and as everyone at MUD knows...post pics or it didn't happen!
Our trip is planned for July 25-29. We're leaving Durango on Monday the 25th and head to Silverton for a top off and last minute supplies. We'll do the Stony Pass Trail and maybe Clear Lake, and camp around Silverton. Tuesday we will be hitting the Alpine Loop, Engineer Pass, and maybe some other trails depending on time Lunch in Lake City and camping on the trail. Wednesday we will explore some of the shorter trails and gulches between Silverton and Ouray, and check out some mines. Camping on the trail at one of the spots recommended here. Thurdsay we top off in Ouray and head across to Telluride on Yankee Boy and Imogene Pass. Some might do Black Bear. Camping at Alta Lakes. Friday we'll run Ophir Pass and head back to Durango for a hot shower and nice dinner.