The 2 trails near calico that would be difficult would be Doran and Odessa.
I ran the odessa trail with the psychos during the calico cleanup and we [h1's ] just barely squeezed through with inches to spare. I don't remember any damage other than the trailer. It took us a while, 2-3 hours to go a few miles. According to the rangers & locals we were the only hummer group that they know of that completed that trail. That being said we did do the trail going downhill which helped. I think the route people were taking was going Doran up and Odessa down. We came in off another trail at the top of odessa, what slowed us down was the trailers on some of the h1's.
Doran is the more difficult trail, and I wouldn't expect many stock vehicles to be able to do it without damage that one I haven't run but I've seen a few vehicles get towed out of there [there's a gatekeeper obstacle at the trail head].
It was a fun trip, I got lost for a while trying to find a group, and there were sponsors running around for the trail clean up event, there was a FRS energy drink truck in the middle of the desert handing out samples. After a while, the 2 girls got sick of the heat, and started giving away as many cases as you wanted. I wound up with 8-10 cases of the stuff tossed in the back. :lol: