Pretty Valley lies in the mountains just above Farmington. The land once belonged to a local landowner who donated it to the US Forest Service. From the car, it's a mile and a half hike away.
To get there, start at the Davis Creek trailhead. Parking is next to a square reservoir at the end of Woodland Drive. Heading south on 200 E in Farmington, turn left just before the cemetery, and continue until you reach the gravel parking lot. Then walk up the road until you come to the trail entrance on the left. It can be easy to miss but there is a small sign that says Davis Creek Trail.
The hike is very steep, and there are sections with no shade which can be tough with the summer sun beating down. Bring a lot of water. Keep right at all of the trail junctions until you reach Pretty Valley. You will know that you've arrived when you pass a cement box as well as a campsite to your left. There are a handful of sites with fire rings scattered throughout the area, some with trees, some without but with a very nice view of Davis County and the Great Salt Lake below. Remember to leave no trace and use established campsites.
There are several cool waterfalls along Davis Creek above Pretty Valley that you can hike to. Follow the sign for Hell Hole Camp on the trail on the way down, or take the other trail from pretty valley upwards.
My friends and I have hiked to Pretty Valley a few times when we wanted a close place to go backpacking. Like I mentioned above, the hike is not easy, but the destination is wonderful. The abundant wildflowers and green leaves in the early summer add to the prettiness of it, although it's a bit more barren by the time July comes around. I also really enjoy the view of the actual valley and the sunset from the edge of the hill.