Duffy Lake trail is not 9.5 miles out and back unless you go well past Duffy Lake, it's 3.5 miles each way, or 7 miles total. Elevation gain is a bit less than you show as well. Says Bryan
The total elevation difference for Duffy Lake Trail is 1,541 feet which is about average. You should count on this hike taking about 8 hours, but of course some folks walk a bit slower and some a bit faster. This is a one trailhead backpacking trail, so you're looking at an in and out backcountry walk. Duffy Lake Trail goes through some very different elevations which of course means you need to be prepared for different conditions on different parts of the backcountry hiking trail. Duffy Lake Trail is 9.2 miles long; it's a long backcountry hiking trail. Keep in mind that this is a long great outdoors hiking trail, so don't forget to pack enough supplies. At parts of the year this region sees very little rain, so donít forget to check for any current fire restrictions before you go.