From the trailhead, descend to the creek and keep an eye out for a tree on the left with a sign that simply says "Trail" with an arrow pointed across the creek. Cross the rocks and follow signs for "Caribou Lakes Trail" or "New Caribou Lakes Trail." From there, it is a rolling, singletrack trail with a lot of variety from pine forest to granite rock slides and lookouts with views of Mt. Shasta. The trail eventually descends back down to the Lower Caribou Lake before a quick climb to the finish at Upper Caribou Lake. There are plenty of primitive campsites at both Upper and Lower Caribou with beautifully clear waters to refresh you.
Once you've enjoyed your time at the lakes, simply return the way that you came, or via the Old Caribou Lakes Trail.