Distance: 21 miles one way
Elevation gain: 2835 ft
This is one of seven rides (all detailed in the Adding Miles section of the Mountain View Road ride) that are worth doing around Boonville, a charming little town with good food and an interesting history, so I encourage you to find a place to stay in the area, make a cycling holiday out of it, and do all of them.
This road parallels Mountain View Road, which is 5 miles to the south, and the two are similar. Both roads are trips through standard coastal pine/redwood forest with a good dose of 8-10% climbing. This one is less isolated that MVR (a vehicle a mile or more), but it’s prettier and easier and it has a better road surface (though it’s still often poor). It makes for a shorter loop if you’re returning on Hwy 128, so if I was just doing one of the two I’d go with Philo-Greenwood unless I wanted a) a bigger climbing challenge, c) more Hwy 1 riding, or c) to visit Manchester. I’ve mapped the ride as one way because I assume you’ll want to return on 128, which is covered in the Mendocino/Comptche ride. The Philo-Greenwood/Cameron Road/Hwy 128 loop is 42 miles.
Begin riding at the intersection of Hwy 128 and Philo-Greenwood Road just north of Philo. The community of Philo is little more than an apple stand (Gowan’s Oak tree—can’t miss it, worth a stop for the apple juice), so you might want to ride from Boonville, 5 miles south of Philo, thus adding about 12 miles.
Head down PGR. Almost immediately you pass the turn-off to Hendy Woods State Park, a lovely stand of old-growth redwoods that charges a substantial fee. Just past HWSP, you begin a hard 4-mile climb, an unrelenting grind that averages 8% but is frequently 10-12%. Almost all of the hard work on the ride is right here. The forest is very pretty—prettier, I think, than Mountain View Rd., though the fact that I rode it after a rainstorm may be the reason. Watch for glimpses of the Navarro River watershed through the trees on your right. Right after the very first little downhill, at 3.5 miles, Signal Ridge Rd. goes off to the L—consider riding it (see details in Adding Miles).
When the bulk of the climbing is over, you roll pretty constantly up and down through more pretty woods, with pitches up to 8%, past scattered farms to the intersection of PGR and Cameron Rd, 15.2 miles in. The road surface, which in the beginning randomly varies from good to poor, deteriorates as you approach the intersection, until in the last miles it’s consistently rough.
At the intersection you have a clear choice. PGR plummets down to the sea (the intersection is exactly at the lip of the precipice, with a sign reading “10% grade (down) 2 miles”). Cameron, to the R, goes to the same ocean in over twice the distance (5.6 miles vs. 2.5 miles) and thus is half as steep. So stay on PGR if you want high drama and smoking brake pads, you want to see Elk (a tiny community with a good diner), or you want to ride the very nice stretch of Hwy 1 north to Hwy 128. Go right on Cameron if you want a relatively mellow and much straighter descent (15-25 mph). I’ve mapped it the mellow way. The road surface remains less than you’d wish but never awful.
Cameron meets Hwy 1 about 1 mile south of the Navarro River bridge. Just south of the bridge, a paved road goes into Navarro Beach, a sweet patch of sand where the river flows into the sea. You’ll find interesting historical placards (it’s part of the Navarro Redwoods State Park), good sea stacks, and driftwood sculpture—well worth a detour.
Shortening the route: Unless you cut PGR drastically short, you won’t save much by turning around, because Hwy 128 is much easier riding that returning on PGR. I’d opt for the full PGR/128 loop.
Adding mIles: I fully expect you to return to Philo via 128, whose praises are sung in the Mendocino/Comptche ride. If you want to make an epic out of it, turn south at the west end of PGR and return on Mountain View Rd. For other rides in the area, see Adding Miles in the Mountain View Road post.
Three and a half miles into our ride, Signal Ridge Rd. goes off to the L and goes 1.5 miles before turning to dirt. I know it’s just 3 miles out and back, but it is a precious three miles I strongly encourage you to do—a true one-lane road that dips and dives deliciously through gorgeous woods on its way to the few cabins that live up the road.
Question: Does Signal Ridge Road go all the way through to Mountain View Road? I’m looking to do as much gravel as possible.
Google Maps says it does, but the real question is, what’s the state of the road? I have no idea.
As of June 2019, Signal Ridge Rd. is gated off at the Mountain View Rd. intersection, and the locals who live behind the gate say that it’s not a through road (and that there are more gates behind that one). Some construction workers nearby also told me that it’s not a “county road.” It’s possible to walk around the first gate.
Sounds like one of those wink-wink nudge-nudge situations where you officially “can’t” ride the road but you really can, if you’re willing to deal with the ill will. I gather there are no “Trespassers will be shot” signs.
That’s right—there was no signage at all at the south end of SRR, or any indication that it is private.
I have discovered that the City of Mendocino has a list of Mendocino County roads, and it indicates that the County maintains 4.36 miles of Signal Ridge Road starting from Philo-Greenwood, until it “ends” which is a little under half of the way to Mountain View Road.
This was a great ride. It was really quiet. The initial climb, while painful, was consistent and manageable (for a weekend warrior). I almost hit a deer doing about 40mph—he jumped out in front of me and I slammed on the brakes. We were both skidding. We were side by side for a few seconds. Took my breath away.
I’ve got more info on Signal Ridge Road! I planned a 2-night loop from Point Arena towards Boonville on Mountain View, then onto Signal Ridge, then back west via PGR. I got to Signal Ridge and easily went around the locked gate. About 1 mile in there was another locked gate with a sign saying “patrolled property – department of fish and wildlife.” I easily went around that one too. the road was dirt with foot-high grass in some places but mostly smooth dirt. I thought I was in for a perfect solo ride…when suddenly I came across a well-cared-for but unoccupied cabin right in the middle of the road. looking at the map I could see that SRR actually went right of the cabin, and I explored that path for a couple hundred yards but it was very overgrown and barely ridable. i was not confident it would get better any time soon, so I aborted. I’m guessing the north end of the road is good for a while but at some point becomes pretty abandoned. probably walkable if you don’t mind poison oak…but likely unridable unless you want a serious adventure. Since I was still curious about PGR i rode down to Hwy 128 in the morning and completed the loop via 128, PGR, and back down Hwy 1 to Point Arena. thanks for the helpful info on your site!
Took the “epic” route today, west on PGR from Boonville, south to MVR, and then back on MVR to Boonville. Awesome ride! PGR is gorgeous, quiet, and shaded the entire way. The climbs on PGR and MVR, especially MVR, are really, really hard, so take Jay’s cautions seriously. The climb going east on MVR from Hwy 1 is ridiculously, shockingly steep for very long stretches. Like one of those private driveways you see in the hills, only stretching on and on. All in all, that stretch on MVR is maybe the hardest 27 miles I’ve ridden. Most importantly, bring plenty of fluids (there is a large, well stocked grocery store in Manchester near the start of MVR) and low gears—34-32 or 34-34 would be even better. Definitely worth the effort, but plan carefully.