It probably wouldn't be an exaggeration to say that Patterson Pass is the most famous road climb around Livermore. The pass is on a backroad that crosses the hills that I believe are part of the Diablo Range, to connect the outskirts of Livermore to the outskirts of Tracy. Along the way, the narrow Patterson Pass Road snakes through softly rounded, treeless, grassy hills that can look like a pastoral paradise in the late winter and early spring, while being forbiddingly hot and dry during the warmer parts of the year. The pass also gives its name to a regularly held road race that passes through it. The loop portion of this route actually follows the course of that race, except that this ride follows the reverse direction (counter-clockwise) of how the race is typically done.

The ride puts the Patterson Pass climb together with its neighboring pass, Altamont, by using it in the return leg of the loop after the route turns around from the doorstep of the Central Valley. Naturally, this is not the "Altamont Pass" that most typical Bay Area drivers might be used to thinking of, which is a stretch of Interstate 580. This is the actual Altamont Pass, on Altamont Pass Road that is part of the historic Lincoln Highway, which crests this range of hills at a little place named "Altamont". While it's true that this traversal of Altamont Pass constitutes the ride's "second climb" as you might expect, this isn't nearly as memorable as the Patterson Pass climb, at least when done in this direction.

Doing the loop in this direction allows you to climb to Patterson Pass the easier (though less typical) way, by approaching it from the west. Approaching this pass from the east doesn't necessarily involve much steeper slopes, but the serious portion of the climb would be roughly twice as long when approached from the east. Approaching Patterson Pass from the east will also fool any rider who's not already familiar with the climb with a "false top", where the grade steepens toward a ridge line where no higher hills are visible, only to disappoint you with the sight of the tough, final stretch of the climb toward the pass when you make it onto the short flat segment that follows.

While your climb toward Patterson Pass in the first half of this ride is very uniform and features a steadily rising grade, the return climb over Altamont Pass will be uneven and continuing in fits and starts, as you can see in the elevation profile plot. To be fair, Altamont Pass itself arrives somewhere around the middle of that climb in the second half of the plot, but even that first half of this second climb isn't very even. The good news is that, with the exception of a short segment on Carroll Road, this climb doesn't have many steep parts. Doing the reverse of this would mean you finish the noteworthy portion of your initial climb (on Flynn Road) in only about a mile, of which really only about half a mile would be serious work.

A discussion of Patterson Pass may not be considered complete without touching upon safety. It appears that this road is known for bad accidents. I read that this is mainly due to its use by commuters who are trying to avoid the congested I-580. The higher elevations of Patterson Pass Road are almost narrow enough to be a single-lane and they are curvy. The riskiness of this stretch is made evident by signs in both directions announcing "pedestrians not advised" and at least one sign in the eastbound direction that prohibits passing for seven miles. The only times I ever rode through Patterson Pass were on Sunday mornings and the road had very little traffic in those cases. Perhaps, that might be the safest approach for this ride in terms of traffic: save it for a weekend.

As the starting point for this ride, I picked a suburban street on the outskirts of Livermore. This means the route involves a short "stem" that you use as the approach and return from the ride's main loop. Part of this takes place on the part of Patterson Pass Road that's in the form of a wide suburban avenue with a wide, paved shoulder, and with what looks like a small industrial park on one side and the boundary of the Lawrence Livermore National Labs property on the other. After its intersection with Greenville Road, Patterson Pass Road transforms from a suburban avenue to a country road in the blink of an eye. After one last straight segment, the road slowly begins to make its way up the hills and you find yourself surrounded by the ride's predominant type of scenery.

As I've touched upon above, the ride's scenery consists mainly of rolling grassy hills that are completely devoid of tree cover, and it's accompanied in places by some tall, modern windmills whose presence on this minimalist landscape produces and almost otherworldly feel. Trees can be found only in the deepest part of creek beds and on the ranch properties along the way. The landscape can look like an inspirational poster, or perhaps like the famous "Bliss" wallpaper that was the default for the Windows XP operating system, when the grass is green. When it turns yellow, which is also when the weather turns hot, it might remind you more of an arid steppe.

When you begin to climb on Patterson Pass Road, you also enter the most secluded stretch of the ride, which lasts until your first crossing of Interstate 580 if you don't count passing by the massive complex of the Altamont Pass Wind Farm Substation. The grade of the climb toward Patterson Pass doesn't begin to pick up until the end of the third mile of the ride, where you encounter a 100-yard stretch with a slope that averages above 10% grade very shortly after the last straight segment's end. Things return to normal quickly after that, and there are short, nearly flat stretches interrupting the climb all the way up to the last mile before the pass. The climb begins to feel serious a little before the 4-mile mark of this route, with about 1.5 miles left to go before reaching the pass. At that point, you climb a segment less than a quarter mile in length, where the end-to-end average grade is 9.5%. There are multiple spots after that where the grade is at or above 13% for brief periods, but the toughest part of the climb is a 300-yard stretch that ends moments before you reach the peak, where the end-to-end average grade is 12.5%. Actually, for about half that distance in the middle of that steepest stretch, the grade stays above 14% fairly consistently.

Reaching Patterson Pass in this direction (from the west) actually produces a nice sense of occasion, which feels appropriate given the tough climb you've just completed. You cross the pass at a curve, and the views to the east that were hidden from you during the climb suddenly open up for the first time only when you take that curve. And the view is a majestic one, with windmills covering the nearby bare, grassy hills and the continuing narrow road twisting somewhat wildly as it heads away from you in a long descent across completely open scenery. Of course, along with the striking scenery, the other reward that greets you at Patterson Pass is the fun descent down the other side. It starts out with a bang where grades reach -10 to -12 percent repeatedly over nearly the first mile and a half. There's a short stretch after that with a gentle uphill where you'll probably have to pedal a little no matter how much momentum you can carry. If you don't count that brief interruption, you won't need to pedal for at least four miles after the pass unless you're trying to maintain a high speed. All of this takes place through a landscape that looks even emptier than that accompanying the climb, at least if you don't count the windmills. When you arrive at the large power substation shortly after passing under a railroad, it's your sign that you're about to turn onto Midway Road.

North Midway Road maintains the character of rural grassland as it takes you over a short climb before beginning to descend toward the freeway and toward more settled areas. That climb is less than half a mile in length, but it does appear to exceed 10% grade in one short stretch.

After crossing I-580, you have a brush with heavier traffic, mainly during your brief stint on Grant Line Road. When you continue onto Altamont Pass Road, the traffic becomes light again, though not nearly as light as on Patterson Pass Road, at least on the weekend morning of my ride. It takes five miles of climbing on this road at widely varying grades to reach Altamont Pass. The grade reaches seven to eight percent in at least three short stretches along the way, but this climb doesn't leave one with the impression of being an especially strenuous one. Your arrival at Altamont Pass will be signaled by your sighting of Summit Garage, whose prominent sign is hard to miss. Arguably the greater significance of this spot is that it's part of the historic Lincoln Highway, the first automobile road (as well as being the first paved road, I believe) that spanned the continental United States from coast to coast in the early 20th century. The stretch of Altamont Pass Road that you cover on this ride follows this road. This is signified by a small sign on Summit Garage. The signage on the facade of this building also seems to imply that it doubles as the Altamont post office, but Wikipedia explains that this post office hasn't been operational since the 1950s.

If you expect another thrilling descent on the other side after cresting Altamont Pass, you'll be a little disappointed because, on this route, you quickly turn away from the road's natural descent toward Livermore in order to complete the loop. Not only that, but actually the worst climb in the second half of the ride arrives here when you turn onto Carroll Road. This climb last for just under a mile, and its first half is its worst part. For the first 250 yards or so of this climb, the grade stays at a touch over 10.5%, though it later scales back to around 8.5%.

When Carroll Road delivers you to an overpass of I-580 and flattens out, the relief is welcome, but there's a little more work to come on North Flynn Road on the other side of the freeway. There are two or three other episodes where the grade briefly exceeds 10% on Flynn Road as you climb through minimalist, grassy hills with windmills towering over you, but the steep parts of this climb are much less persistent. Flynn Road crests its own unnamed pass, which is actually much higher than Altamont Pass, shortly after a sharp, righthand curve. Only then do you get to have your second thrilling descent, with views of Livermore in front of you, over the next two miles. At the bottom, you complete the loop portion of the ride when you reach a junction on Patterson Pass Road that you had passed before, and turn right to pedal back nearly flatly to your starting point.

After your ride, Livermore is an obvious option if you have time for some food or drinks. I haven't spent enough time here to have multiple "favorites" I can point out, but there is no shortage of enticing options. One restaurant here of which I've been a repeat customer is First Street Alehouse, and it's an easy recommendation to make. It's a big place, yet popular enough to still make it difficult to get a table on a weekend. The menu seems focused mainly on comfort food and pub fare, with burgers (which looked good) apparently their specialty. While I'm not a big beer drinker, if the frequency with which the Pliny the Elder beer is mentioned on MTBR is any indication, then it's probably a detail worth mentioning for some mountain bikers that this particular pub is one of a limited number of places where this fine brew is served.