Three Peaks In A Day

Mt. Tamalpais
Mt. Diablo
Mt. Hamilton
Mt. Hamilton

Looking for a challenge? How about riding Mt. Tam, Mt. Diablo, and Mt. Hamilton? In one day, that is.

The Bay Area is blessed with three major mountains within riding distance of each other, Mt. Tamalpais, Mt. Diablo, and Mt. Hamilton. These are not the highest peaks nor the only ones—there are many in the Santa Cruz Mountains alone including some that are higher. However these three do stand out because of their relative separation from other nearby mountains and because they have paved, public roads that go to their summits. You’ve probably climbed to at least one of these peaks, if not all three. If you like to climb hills, you have probably contemplated the idea of doing all three in a day. That’s what this article is about: planning an assault on all three mountains for next spring or summer when the days are longer and the weather pleasant enough.

There are several ways to go about an assault. I’m going to go through each one in some detail below.

The Full Monty. The real deal is a full-on ride to all three peaks and return to the start in a continuous circuit. If you start in San Francisco, that means eventually returning to San Francisco by bike. This would be more challenging than Bay In A Day because it involves not only circumnavigating the Bay but also climbing three peaks. A rough estimate of this route is 276 miles and 21,000 feet of climbing! One could make this less painful by splitting it up into two days.

Realism. A lesser if not equally noble goal is to ride up all three and back down, say starting in SF and ending back at the bottom of Mt. Hamilton in Milpitas. This gets all three peaks completely by bike. Using San Francisco as a starting point, this would mean, for example, riding up Mt. Tam, riding over to the East Bay by Highway 37 to do Mt. Diablo, and then riding south to go up Mt. Hamilton. However, getting over to the East Bay the shortest way still entails riding on Highway 37, which has high speed motor traffic—not the safest route! This is roughly 210 miles and about 2,000 feet less climbing.

Realistic and Safe. More practical assaults would use public transportation—either BART, the BART bike shuttle, or a ferry—to avoid having to pedal over to the East Bay by Highway 37, with the most honest route minimizing use of BART by getting on at Embarcadero and exiting at West Oakland; another possibility is to get a car ride over to Treasure Island from the Embarcadero and then begin the eastern stretch there or perhaps catching a ferry at the Embarcadero and arriving at Alameda or Jack London Square. Starting in San Francisco and ending at the Warm Springs BART station in Fremont this route is about 208 miles and just 17,200 feet of climbing.

Realistic, Safe and a Bit Shorter. This option cuts out riding through Oakland and takes BART directly from SF to Walnut Creek. Starting in San Francisco we would ride to Marin and ascend Tam and return to SF and take BART to Walnut Creek, go up Mt. Diablo and then ride to Mt. Hamilton and ascend, probably up the front. This route is 185 miles and has 15,700 of ascent.

Keep It Simple Stupid. Instead of riding from Mt. Diablo to Mt. Hamilton, we could take BART from Walnut Creek to the Warm Springs BART station, which should be open by this spring. This cuts down on the ‘junk’ mileage. This route is 152 miles and 14,800 feet of ascent.

Keep It Simplest Stupid. However, ascending all three peaks by themselves requires climbing well over 10,000 vertical feet. You could reduce the effort by just riding up the mountains and skipping the mileage to get between each one. For Mt. Tam this might be beginning the ride either at Tam Junction or Mill Valley and ending there; for Mt. Diablo, beginning at the Athenian School at the base of South Gate Road (North Gate is a longer route with slightly more vertical); for Mt. Hamilton, beginning at the base of Mt. Hamilton Road. This route yields about 11,500 feet of vertical ascent over 83 miles. Note that these routes require having a car in order to start the ascents at their bases.

A full circuit of the Bay and the peaks is beyond the reach of all but the most stubborn randonneurs. Using a car to reduce the mileage just to climbing up the ascents by the shortest means possible (Keep It Simplest Stupid) seems like cheating because of the liberal use of a car. That leaves the middle three as distinct possibilities with the Realistic, Safe and a Bit Shorter alternative as the ultimate goal. Even this option is super strenuous: doing a double century such as the Davis Double, which is fairly flat, is an all-day affair with the likelihood of needing to use lights. Now add three peaks and no organized support: even on the longest day of the year you’re very likely going to be riding in the dark either at the start or the end.

The most realistic option is Keep It Simple Stupid. At 152 miles it is longer than a double metric and boasts total vertical that is only a bit below the Death Ride. Even with an early start it will be a long day and logistically one would plan it around the Summer Solstice in order to maximize daylight. However unless the weather cooperates and is unusually mild Hamilton and Diablo are likely to be very hot in June. In order to avoid draining heat it would be better to plan this assault for late April or early May, which shortens the day but reduces the temp.

As training for the assault, doing a few  doubles would be good practice, e.g. Tam plus Diablo, Diablo plus Hamilton, or Tam plus Hamilton. These are pretty doable and cut the mileage and elevation gain by about a third from Keep It Simple Stupid, making for a 100-mile day with about 10,000 feet of gain.

8 thoughts on “Three Peaks In A Day

  1. Wow, super tempting!
    I did 37 a few times, most of it is ok (not super fun). The scary part is the bridge at the beginning, since there are no shoulders. But it’s rather short
    I am going to try to map some of your options.
    Question: aren’t there any ferries that go from Larkspur to Vallejo or the East Bay?


    1. Unfortunately there aren’t any direct ferries between Larkspur and Vallejo. You have to go to SF and then catch a ferry to Vallejo. That might be a pleasant, restful interlude before tackling Mt. Diablo. But then you would almost certainly end up riding in the dark on the Realism option. (It’s a foregone conclusion that you’d be riding a LOT in the dark for the Full Monty regardless of how you got between Mt. Tam and the East Bay.) Generally Hwy 37 just isn’t safe for cyclists in my opinion. However it would be safer to ride it when there is the least amount of (drunk) traffic, say, maybe very early Sunday morning. I’d use my brightest taillight too. And a mirror. And I’d go like hell to get it over as quickly as possible. That said, I have become increasingly risk-averse as I get older; therefore I’d rather ride back to SF and just take BART to the East Bay!


    1. Of course, “easier” only relative to doing it clockwise. I think 300 miles in a day regardless of direction (and 20k feet of elevation gain!) is excruciatingly hard, period. Wind direction might be critical. Clockwise you probably fight the wind all the way back on the Peninsula; counterclockwise you probably still have wind in the East Bay and then you have to grind over Hwy. 37. Into the wind. In traffic. Um, no thanks! If you omit Hwy. 37 as part of the attempt, then counterclockwise might increase the chance of success. Doing Mt. Tam at the end might make sense too because it’s the easiest of the three peaks.


  2. A friend of mine did this in September, here’s his route:

    They did it clockwise starting from a friend’s house near Diablo and ending in SF, total of 262 miles and 30+ hours (including breaks). You are totally right, they were hating the overnight wind on the peninsula heading from SJ to SF.


    1. It looks pretty brutal. The only things I would have changed: (1) I would have gone up South Gate instead of North Gate Road; (2) Going up the back side of Hamilton is steeper but it’s shorter than getting to the SJ side and going up Mt. Hamilton Road (I’m not sure which is less gruesome); and (3) I would be so tired by after Hamilton that I would have stayed on the flats on the Peninsula, either rolling on Bay paths or even going up El Camino Real (depending on the time of day I had to do it). If your friend did it alone, then extra kudos for not having some others to share the workload fighting the headwind.


  3. Tony, I would never do that just by myself. I did it with a friend, but sharing the workload won’t be possible in the sense that riding midnight while cold and tired, we were barely holding ourselves up let alone taking turns drafting each other.

    But it was fun and stupid adventure. I would never ride it again tho, haha


    1. Total props for the accomplishment. I read your account and you made it sound so easy. Until the Midpeninsula! I think doing it with others would be helpful, nay essential, not just for any sharing of workload but for the mental component as well.


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