The first part of this trail is the upper portion of Ditch Creek Trail. Approximately 0.7 miles from the trailhead, the unsigned 0.3 mile Rainbow Lake Trail splits off to the left. In another 1.8 miles, the trail junctions with the Caton Lake Trail. From the Ditch Creek/Caton Lake Trail junction to Caton Lake is 5 miles, and another 0.8 miles to the boundary of the Boise and Payette National Forests. The trail weaves in and out of trees, large open wet areas, and meadows. After climbing slightly, the trail drops gently for several miles. The trail then passes through Caton Meadows, climbs to a low saddle, and drops sharply to Caton Lake. This trail begins approximately 0.7 miles up the Ditch Creek Trail. It is not signed, but the trail is obvious and takes off to the left. Mature pines provide nearly continuous shade as the trail makes its way .25 mile down to the lake. Just before the lake, the trail passes through a medium sized campsite, and then out of the trees onto a small marsh at the south end of the lake. Rainbow Lake is lovely and clear, though steep sides and encroaching forest limit the shore.