Steep grades/roads atlas or directory

We are returning from Moab Utah to Michigan. We did it in a 2008 Damon Challenger 378 towing a 2dr Jeep Wrangler. While going over the 11,120' pass I had a "CHECK TRANS TEMP" warning so I pulled over and let it cool down then unhooked the Jeep and the DW followed me through the tunnel. I re hooked the toad and went on our way. I ended up in first gear going 30mph that's when I got the warning. I then learned that pulling grades like that you should never push it that hard. I was told to keep it in 1st and only go 15 to 20 mph and it should be fine. I just wish I would have known about that before I did it that would have helped keep my stress level down. On the other hand Moab is great I hope you have reservations already taken care of most campgroungs were full.