The Campendium reviews of FR611 seem mixed, but seem to lean towards bad road in, and if you go far enough, eventually a difficult/impossible turn around, but there were one or two that said it could be done. However, they weren't all large vehicles or actually pulling something from the sounds of it. A 32' motorhome and 2 Airstream trailers made it in, and I assume, out.
It looks like, once you're past the 2 access points to "Dog Canyon Apron" (zoom in on google maps to find it), it's a one way road, from google maps.
If it were me, and if you didn't find a spot you liked on the way in, I'd drop the trailer near there, and scout it to the end with the truck, before continuing towards what looks like a dead end.
Sounds like once you settle in, it's a great place to stay.
