Starting on Campo Rd. in Jamul, take Lyons Valley Rd. east. After 1.7 miles, turn right to stay on Lyons Valley Rd. After another 8.9 miles, you'll hit the Lyons Valley Trading post. Shortly afterward the road will turn into Japatul Lyons Valley Rd. then Japatul Valley Rd. which will take you north to I-8.
This route starts out on some easy light rural roads, but then turns into dusty ranchland with tight turns and boulders throughout.
This road has a lot of tight twisties and elevation changes to keep it interesting, going from dusty ranchland to wooded grasslands. Road is mostly smooth asphalt but watch out for dried mud and gravel, especially after any recent rain.
The Lyons Valley Trading post is about 10 miles in, but there is no gas along the route. Plenty of gas is available at the start of the route in Jamul.