This adventure goes on both on and off trail. It begins at Agnew Meadows near Mammoth, California. Take the PCT High Trail to Thousand Island Lakes. From there, run to the backside of the lake along the trail then climb to North Glacier Pass. For about 12 miles this route follows the idea of the Sierra High Route but you are not limited to the exact route. If you can find a better way across the section from North Glacier Pass until the Isberg Pass Trail, you’re free to make up your own version through this area (open course) as long as you are hitting Lake Catherine, Twin Island Lakes, and Blue Lakes. The section between North Glacier Pass to Blue Lakes Pass is a large mix of talus and grassy areas with stunning views! You will most likely not see another soul through this section, and you are far from help, so be careful. There is plenty of water in numerous streams and lakes. Once you connect to the Isberg Pass trail, stay on it until you make the connection to Merced Lake. From there, stay along the Merced River trail until Nevada Falls and then finish at Happy Isles in Yosemite Valley on the John Muir Trail. There is over 12,000 feet of drop in elevation over the course of this route. Depending on how wet the season is, there will most likely be at least two water crossings that are very manageable (Twin Island Lakes and Lyell Fork of the Merced River). If you can time it well, and keep a good pace, you could catch the YARTS bus in Mammoth at 5 PM during the regular season and take the bus back to Mammoth. That way you don’t have to have a pick up or stash a car. Good luck!!
