Why would you bike 1850 vertical feet just to look at a tree? If you have to ask the question, you aren't a mountain biker. The Jardine Juniper Trail is a nice hill climb, and worth doing just for the ride. At its end point there are great views, plus Utah's oldest tree -- the Jardine Juniper.
If you ride the circle at the end of the trail, plus the path down to the juniper, you'll cover 11.4 miles (round trip). Starting altitude is 5350 feet, with peak altitude at the end of the ridge of 7200. The ride is upper-intermediate overall, with a riding season from mid-June through October.
This is one of the best intermediate-biker singletrack hill-climbs in the state. You should add the Jardine Juniper to list of "Great Rides I've Done."
Camping: Woods Camp
Bathroom: at trailhead
Water: campground
GPS track files (right-click and "Save as..."):
  GPX track
Topo map: View map
Single-page riding guide
Lodging, camping, shops: Links to Logan resources