JB, you sound like my kind of off roader!

Mine's a daily driver so it needs to get me there and back and I don't get in a hurry. I'm no Baja racer like some I've seen on trail. Besides we like to enjoy the scenery while we're there.
I like the Well's books because you can read his detailed description and pretty well know exactly what parts of a trail might give you trouble while you're still at home.
Example here. His time estimates are very good. Makes it easy to plan a trip before you go. I have both Volumes of Colorado but Vol 1 has my favorite areas and I have the Arizona book. He also has Moab and California books.
You're right on the nose about the trail descriptions and vehicle sizes. A suburban is what slid off into the Punch Bowl and killed 7 people around 1970. Your basic stock 3rd GEN or older 4Runner has enough clearance to do this trail without damage. The lowered and wider 4th GEN will have some trouble. You wouldn't think a couple of inches in width would make a lot of difference and it usually doesn't except for that one spot on this trail. It's possible that this one rock was not previously there and fell later. I ran the trail for the first time in 2000 in my 3rd GEN. From July on the vegetation at the top of the trail will get higher than your vehicle and you almost have to push through it so you will get trail rash. There's no where to turn around and in that section you can't see anyone coming until they're 10ft away.
The Crystal Mill is accessible by car (part of the problem) from the town of Marble. I'll dig my pics out. I'd posted them here but took them down with the new forum rule about not being 4 Runner related. There is SERIOUS signage to keep people from driving farther up.
Being used to a stock 2001 4Runner, I took my stock 03 to run some Arizona trails. Very capable but dang the front end was LOW compared to the 01. I quickly learned that I needed a lift to continue to run the kind of trails I was accustom to or I was going to leave parts behind. Don't get me wrong, stock is very capable but it made me too nervous to enjoy it as much. The 3" Revtek gave "slightly" more clearance of the stock 01. I've been extremely pleased with it.
The skid plates on the 3rd GEN will give you some protection but they're very thin and will crush at some point. I work real hard to not use them. My Running boards quickly came off so I wouldn't drag them off.
Peak season in CO is 4th of July through August. I've run the trails from late May to early October. Each month's weather is different. Cold and snow with limited access in May, June, October. July will have cold mornings, warm up quickly, and afternoon thunderstorms and rain. This is not bad because it keeps the dust down and washes all the dirt off daily.

August is warmer and dryer and dustier. Fall colors come on in September as to high pass snows. They may or may not melt overnight. The colors are awesome!!
Crowds? More so every year but they're never that bad. There was a national Jeep jamboree in Ouray last year which made lodging tight but the trails were not bad. If a large group is caravaning they "might" let you pass or you can wait them out for a while.
All other factors aside, I personally like July. The wildflowers in the passes are in full bloom and will knock your socks off, but it WILL rain. If that bothers you, pick August. I can run with the windows down in July and not get dusted much but if you do that in August you'll bring 30lbs of Colorado dust back on your seats.

I've had to run with the A/C on in August because it was so hot and dusty. I like the windows down to smell the pines and hear noisy Jeeps coming.
I've learned to do breakfast at 6am and be "on" the trial at 7am. You'll virtually be by yourself for the first 2 - 3 hours until the on coming traffic reaches you. It works. I highly recommend that technique when going up Engineer from the Ouray side. The lower section is doable at stock but it's EXTREMELY rocky and you will need to GO SLOW so you don't want to have to mess with others passing you. That's the only "bad" section of Engineer so if you want to by pass it you can always do the Alpine Loop from Silverton via Animas Forks which meets Engineer at the half way point then on to Lake City and return via Cinnamon Pass. There are several routes from there back to 550 with out taking the rough section of Engineer back to 550.
Imogene is fun and very popular. It and the bottom of Engineer are slightly more technical than some of the other trails.
I can go on for hours if you like. Can you tell I like the Ouray area?



