3speed

A friend and I are leaving for Seattle in a week to ride down the coast. We'd like to hit some light-ish off-road routes along the way if possible. He'll be on a Salso Fargo and is taking his 2.2" Race King MTB tires. I'll be on a touring bike, but have some cyclocross tires to put on. I'm a MTBer, so I should be fine with those tires on some mildly sketchy single-track, and I don't mind walking a few hills if need be, but being limited to 700x35 tires, I can't do anything too intense. Any dirt and gravel should be fine as long as the rocky parts don't get too big of rocks. We're both up for taking some food and hitting a long off-road route for a few days before returning to civilization to restock on food, water, etc. Are there any such routes along the west coast?

niknak

In California, you'll have the opportunity to ride out to the Lost Coast. Some of the roads out there are unpaved.

Further south, you can ride along the Bolinas Ridge Trail. The north end of the trail starts near Samuel P Taylor State Park (which has a hiker/biker site). The trail ends at Ridgecrest Blvd., where you can take an optional and highly recommended ride to the top of Mt. Tam. From the Mt. Tam area there is a network of scenic paved roads and trails that can pretty much get you to the Golden Gate Bridge. Here's a route that I've ridden. The AC map does a good job of guiding you through the urban jungle of Marin County, but the route I linked to will provide better scenery and more peace and quiet before you enter the madness of San Francisco.

fietsbob

We got a lot of logging roads , but they are about getting the Timber out, not getting anywhere , point A to B.

enigmaT120

Still, one of my long term goals is to map a route n - s along the Oregon coast range. I'd start with the area between highway 22s and 34, of course, since I live in between those. And east of the crest by only about 10 miles. The roads are closed to public entry for now due to fire danger, but maybe we'll get enough rain this week to change that. Much of the year they are closed to motor traffic but open to pedestrian and bicycle traffic.

This route would involve a lot of sometimes hard climbs on loose gravel, but no single track. And Bob's right, the roads are about removing logs from the woods and tend to be east - west networks, not n - s.

NordicNorm

I'd start with a set of Atlas Gazeteers - very detailed maps. Sounds like an awesome ride.

B. Carfree

The forest service, part of the USDA, has complete sets of paper maps of all the national forests. While they are occasionally out of date, they do indicate the surface of the roads so you can select the unpaved ones (and only occasionally get surprised by paving that happened after the last map update). A lot more roads go through to decent connections than not.

While the forest roads rarely go truly north-south, they do form nice networks if you don't mind doing a lot of southeast followed by returning over the crest southwest and then repeating. Yes, you're going to do some climbing, but in between you will be cruising along the rivers and large creeks.

While I could give you some proper maps from Newport OR to somewhere in Coos County, you'll have more fun if you select your own roads. You can even use Google Maps, although be sure to check other sources since Google is notorious for thinking roads that go through (like Upper Smith River Rd near me) don't do so in the coast hills.

Definitely ride the Lost Coast. Climb the (paved) backside of the "Wall" out of Ferndale and head off onto the unpaved stuff at the top. You'll end up on some pavement, but you can get off it again at the top of Wilder Ridge. Chemise Mountain Rd and Usul Rd are unpaved and awesome. There are also some unpaved roads in southern Mendocino County and northern Sonoma County, but I haven't been on them in so long I can't give you any info.

SparkyGA

Another vote for the Lost Coast area. It is some seriously fun riding around there, but I hope your geared LOW

stevepusser

Also inland from the Big Sur Coast in the Los Padres National Forest--head inland up the Salinas River Valley from Monterey Bay to Arroyo Seco, then thorough the Coast Range over to the coast near San Simeon.

Jseis 

The Oakville to Raymond route via Brooklyn is pretty off the beaten path. Some paved, some gravel. Then from South Bend to Palix on that road. There are others as well but piecing an entire route would be a challenge.