There are three tunnels in Yosemite. Two of the tunnels are on Big Oak Flat Road, between Crane Flat and the Valley. These tunnels are fairly short. You will have to pass through these tunnels if you are using 120 to get into the park. The road from Crane Flat to the Valley is windy and parts have a low rock wall along the road. Like Frank said this could be hairy if you don't like to be crowded. Plus your passenger gets a good view of nothing on the other side of the block wall
.
The other tunnel is on 41 coming from Oakhurst. This tunnel is about one mile long. There is plenty of room inside the tunnel. Be sure when you exit the tunnel on the valley side that your speed is SLOW
, lots of pedestrians cross the road here. If you stop,(parking for MH's on the left side just past the tunnel) on the Valley side of the tunnel, you can walk back into the tunnel on the side walk and 1/4 mile in is a shaft (carry a flashlight) going out to the side of the mountain. Great views from there of the Merced River, but beware of honking horns, sandy uneven footing, and the noise
. Not a hike for young children.
Andy you didn't say what time of year you were going, but I'll bet you could get the Alpine in there at Lower Pine or North Pines in the Valley. Reservations required.
We have been through Yosemite 2 round trips with the coach. Traveling from Fresno to Lee Vinning, going through all three tunnels, and never had a problem. We have yet to stay in the park with the MH. One day we will spend a week at Tuolumne Meadows campground. IMHO the prettiest part of Yosemite.
Safe journeys.