This is an astounding ride which includes two of the best roads in the Bay Area. Morgan Territory is particularly notable; a pretty climb with virtually no traffic, and a long roller-coaster descent on a wide-open one-lane road. Palomares Road at the end of the ride is no slouch either. There’s a stretch of almost 50km, from Clayton into Pleasanton, where there is no civilization at all. Traffic ranges from nonexistent, on Morgan Territory, to heavy through Dublin. Plan to bring extra food and water, and to be in shape before you attempt this ride. No real beginner or intermediate route here, though there’s a bail-out at 64km in Dublin (still a hard ride).
Concord Boulevard/Clayton Road
Concord Boulevard is a moderately busy, boring road with a decent shoulder. Clayton Road is a busy, boring road with some decent shoulder. Gotta ride ‘em, they’re the only way out to Clayton.
Marsh Creek Road
Marsh Creek is less busy (rural rather than ex-urb), but narrower. It includes a non-trivial climb and a fun descent. On the descent run-out, bear right on Morgan Territory Road. Don’t waste your momentum!
Morgan Territory Road
Morgan Territory is among the best biking roads in the Bay Area. It’s one lane and beautiful for most of its length, with virtually no traffic. The climb from this side is wooded and comes at you in waves; it’s only about 300 meters climb but it feels like more. The pavement tends to be spotty. There’s a regional park at the top which usually has water, but I got up there once on a hot day and the fountain was off. Be prepared. After the peak there’s an incredible technical descent on twisty, steep, wide-open one-lane road. There’s still almost no traffic, but this is a two-way road, so be alert for cars potentially coming up the hill at you.
Manning/Carneal/Collier Canyone/Highland Road
This is a collection of winding, rolling roads through farmland. They tend to be hot and windswept but otherwise pleasant.
Camino Tassajara/Windermere/E Branch/Dougherty/Amador Valley
These used to be fun biking roads; now they’ve been taken over by burbclave traffic.
San Ramon Road/Foothill Boulevard
The one bail-out this ride has is here at West Dublin BART. Foothill is a fairly nice road, somewhat more traffic than you’d prefer, but usually there’s enough room to share.
In contrast with Foothill, Pleasanton/Sunol has little traffic and wide shoulders. It parallels active and deteriorating railroad tracks. There’s one climb, more an incline than a hill. The road ends on a downhill at Highway 84.
Niles Canyon Road (Highway 84)
Be sure to hop off Highway 84 at Sunol to take a rest in this tiny rural town. Other than that, Niles Canyon is a beautiful and unpleasant road; the canyon is the beautiful part, the traffic is the unpleasant part. There’s a lot of it and it moves fast. Most of the road has a good shoulder, but there are bridges and other narrow sections which can be harrowing. The turnoff for Palomares Road (intermediate and advanced rides) comes immediately after the road goes under a railroad trestle; it’s a steep switchback to get onto Palomares, so be ready for it.
Palomares is a very nice wooded, rugged road with little traffic. The climb is alongside a creek, and has some steep sections peaking at about 400 meters. There are a couple of wineries along the way. After the peak there’s a fun descent into Castro Valley. Keep bearing to the left as you near the bottom; Palomares becomes Palo Verde and then E. Castro Valley Blvd.