I thought Jolon Rd would be a good connector between the Monterey and the Paso Robles areas. The road itself is fine: not too busy and a wide shoulder. But as it turned out, there are a number of other issues:
Going South on Carmel Valley Rd and Arroyo Seco Rd to Jolon Rd doesn't work. When I was in the area, Arroyo Seco Rd ended for me at the entrance to the campsite. More research on the net revealed that the road continues indeed, but it's closed to traffic and is not paved (at least significant sections of it).
Getting from Naciemiento Fergusson Rd to Jolon Rd also is a problem. You need to take Mission Rd through Fort Hunter Leggitt and bicycles are not allowed on this road. This also prevents you from riding to the San Antonio de Padua Mission which is located righ in the center of the Fort not far from the Randolph Hearst's former hunting lodge.
Finally, Interlake Rd would be your connection to Paso Robles, but I didn't like the road: no shoulder, high speed traffic and big trucks towing even bigger boats ...
Halfway up the climb coming from King City - looking up and down