Fantastic trail. If you don't want to pay for the ferry, you can park at String Lake and hike just 1.7 miles to the trailhead, saving 2.2 miles vs the hike from the Jenny Lake trailhead. once you complete the initial switchbacks which are somewhat strenuous, the remainder of the trail is a gradual climb up the canyon. Even if you can't complete the full trail, don't stop at the trail junction at the top of the switchbacks. One further mile into the canyon opens up views and vistas you don't want to miss. I had the luck to see two moose across the creek and encounter zero bears. Do being bear spray and hike in a group.