On the Upper Kern there are six different runs possible. Depending on who you ask, they are known as the Limestone Run, Fairview Run, Chamise Gorge Run, Gold Ledge Run, Camp 3 Run, and Powerhouse Run. The Chamise and Gold Ledge Run are the two most difficult of the six, dropping more than 60 feet per mile on each. Both are class IV+/V runs. The Limestone Run is perhaps the most favorite of the six and drops 44 feet per mile.
It is possible to combine runs but know where the portages are in advance. Inquire locally about known dangers. Salmon Falls (VI) is right after the take-out for the Chamise Gorge Run. After the Limestone Run there is a dam... Don't float over it. Scout takeouts in advance.
