The Franklin Trail is 10.25 miles each way from Carpinteria to Jameson Lake. The south end is at Carpinteria High School and starts enclosed in fencing. This opens up to tight switchbacks through rock outcroppings that climb to utility roads. The utility roads are well signed as the route twists and rolls through the foothills. At 5.2 miles, there is a sharp turn onto singletrack where the trail leaves the road and climbs to the top. This section is all singletrack, rocky, and technical. After 8 miles, the Divide Peak OHV Route is reached where a sign is marking the top. The trail continues directly across this but may be hard to see. Follow the overgrown flatter area west through reaching trees and it should become easier to follow as it goes especially once past the power line tower. After descending down into the canyon you should be able to spot Alder Creek Camp which is about 0.6 miles below and easily recognized. Blackberries toward the bottom can make travel there difficult as well as the initial navigation up the trail from that side. The route is slightly less travelled on this side but for the most part the trail is on the East side of the creek (almost exclusively). Once emerging out of the singletrack there is about 0.3 mi of double track to the Jameson Lake historic trail sign. From here it is a small distance down to the boat launch which is the turnaround point of this route.
Franklin Trail (double) attempt - I submitted this route to FKT.com about a week ago in anticipation of my trip here. I am going to attempt this tomorrow (2019-12-28) going for the double run to the lake and back. With any luck I should be able to establish a "unsupported single" FKT and also a "self-supported double" FKT of this route (as of now the plan is to self crew myself in the school parking lot (trailhead) at the start of the route to resupply my water). I will document everything via my Garmin and provide pictures and a blog write-up to support the adventure with all the details.
I completed this attempt - pending FKT validation. You can view my adventure blog report here: https://trevormeding.blogspot.com/2019/12/franklin-trail-double-fkt.html. It has link to all my STRAVA data and details my day.