The official park position on vehicle lengths can be found here.
After taking Jolly (sans Tana, she stayed at the campground) into the Yosemite several times, I can tell you there is NO way in the world we would ever take a Montana in there no matter what the official statements may say..
For the route on 140 arriving from the east heading towards El Portal, we are too long, if the signs of 45 foot TOTAL are to be believed as well as the $270.00 fine if you decide to try it and get caught. Yep, Tana and Jolly are too long, almost 53 foot when hooked up and running. However, if you study the official position, it seems you can pull 60 foot combined?
There are tunnels that are less than 11 foot at the inner edge, so, try that and it will be good bye Montana roof. Check out that height warning sign, nope, Tana is not 10 foot 4 inches at the side.
A couple of rocks protrude OVER the roads, they have most of those cut back to about 13 foot 6 inches. Tana actually would fit under this, but, why??
That stone is so hard, I shudder to think at the roof damage, ewww. Tana would technically fit, but, just looking at this gives me the heebeejeebees.
This is Arch Rock Entrance on 140 east of El Portal at the park entrance. I drove Jolly through there and it was, mmm, interesting. I had a hard time finding measurements for this entrance on the internet. I finally did find one reference that indicated it was 14 foot tall. Since Jolly fit through, width wise, Tana would have as well. Generally speaking, if Jolly and the big butt fit through, Tana will fit through, in the WIDTH. That said, we could not get here due to the length limitation of 45 feet (noted above).
So, that's my story and I am sticking to it, as they say. We will keep parking/camping with Tana outside the national parks for now. Thanks anyway - -