The Block U, as it is properly called stands on the hill above the University of Utah campus. Houses have encroached on the U since it became the 2nd block letter built in the US and the first in Utah in 1907.
Now you park in a neighborhood and take a short walk through a few backyards (not really, there is a path) to reach the sidewalk below the U. There are signs that say to stay off the grass, and climbing up to the U is being discouraged, but you can get within 35 yards of it and still be on the pavement.
The U was reconstructed in 2006, and currently has lights embedded in the concrete so that it can be lit for special events.
To access the U, you need to get to 1300 East. You can take Foothill Drive and it turns into 1300 E, or you can come up from 600 S and turn onto 1300 E. Head north on 1300 E to South Temple. Go East on South Temple and turn left (north) onto Virginia Street. Turn Right on Chandler St. Turn Right on Tomahawk Dr. The trailhead is on this road at the dead end.