“Climb up to Flagstaff Hill via the old Salmon Falls Road.
— Matt Hindman
An alternate route splitting off from the popular Salmon Falls Trail (aka Darrington Trail) near Lake Folsom, California. The trail splits off from Salmon Falls Trail just after the switchback at Hancock Creek and includes a very steep climb ( > 20% grade in some sections) up to the top of Flagstaff Hill, which is a granny gear trail at best.
Be sure to take a right after Hancock Creek instead of a left.