This trailhead was very unexpected, but quite nice. I've not hiked a lot up this part of the…read morecanyon--my teenage years were spent in the canyon, but we always took the fork to Tibble and rarely did I go up and over the Alpine Loop, or even anywhere along UT 92.
Once you pass that aforementioned fork to Tibble, the road does narrow a bit. I drove the loop last fall and it was tense--bumper to bumper cars trying to take in a weekend drive of the foliage and not very enjoyable when the road is really only wide enough for one direction of traffic.
The good news is that this trailhead isn't far past the fork at all, so we made on large hairpin, one tight one, and boom, it's there on your right (if you're coming up from the Lehi/Alpine side). It's a generously-sized parking lot, has restrooms, signage, and is a great starting off point.
We took the Pine Hollow Trail #47, which is the namesake, obvs. We crossed the road, went up, and took the loop clockwise that goes up to some killer views of the back side of Timp, and then comes back down to Salamander Flat near the road, before cutting back up into the forest, meeting up with Trail #47 again, and retracing the steps back to the trailhead. You can, however, launch off from here, and go all the way up to Mud Flat and pop down at Tibble, if you're after a longer hike and have a shuttle set up.
The hikes here are lovely, probably even moreso in Autumn. The very very earliest of leaves were already starting to fade a bit, so get out and make hay while the summer sun shines. Not a massively popular trailhead, but due to its size and convenience, you'll see plenty of folks doing just that. Keep an eye out for bikes and motorcycles on the trail; we saw both.