Mt. Hamilton

Distance: 36 miles out and back
Elevation gain: 4750 ft

(A Best of the Best ride)

(Note 2021: Lick Observatory is closed due to Covid, though there reportedly is a water refill source near the gate.)

This is a grande dame of a ride, one of the three iconic climbs in the Bay Area—Hamilton, Mt. Tam, and Diablo.  It’s quite long—18.2 miles one way, all but a mile or so significantly up.  It’s much more sustained climbing than either of the other two icons, and it’s considerably over our 100 ft/mile benchmark for climbing difficulty.  Still, it’s easier than the numbers make it look.  When they built the Lick Observatory at the summit, starting in 1876, they needed to haul massive equipment up the road by mule, so they had to make the road at a shallow enough pitch that the mules could handle it.  So it’s a constant 5-7%—not a moment of 8% in the whole 36 miles.  And there are two nice descents along the way up to rest your legs.  Nevertheless, it’s work, just because there’s so much of it. You’ll be climbing, with two brief breaks, for something like 3 hours.

The route is all through pretty East Bay oak-strewn hills, and the road contour is constantly rewarding (endless serpentining) after the first couple of miles.  The vistas of San Jose, the southern end of SF Bay, and lands to the south start out grand and get more incredible as you ascend.  The descent used to be hampered by poor pavement, but the road from the observatory to Grant Park has just (in 2021) been repaved and now it’s all flawless and world-class.  And the observatory at the top is simply fascinating. All in all, a bucket-list ride, marred only by the fact that 16 miles of essentially unaltered 6% climbing gets a little monotonous.

(To see an interactive version of the map/elevation profile, click on the ride name, upper left, wait for the new map to load, then click on the “full screen” icon, upper right.)

Start at the beginning of Mt. Hamilton Rd., where it takes off from Alum Rock Rd.  The Berryessa BART station will get you within about 4.5 miles of the start (so 9 miles round-trip) and will add c. 400 ft to the elevation gain.  If you drive, there are dirt pull-outs for parking on both sides of Alum Rock Rd. at the intersection, and there is plenty of curbside parking available in front of houses in the nearby neighborhoods.  There is no flat road anywhere nearby to warm up on, but the pitch of Mt. Hamilton Rd itself is mild enough that you can warm up on the climb.   The first couple of miles ascend rather monotonously up a sidehill, but soon the pitch lessens and the road begins to serpentine deliciously, and it will continue to do so to the end of the ride.  When the road surface turns poor, you cross a ridge and get a 2-mile descent to Joseph D. Grant County Park, in a pleasant green valley (during the rainy season) between the hills with trails, campgrounds, bathrooms, and water (there’s a spigot right across from the money collection kiosk at the entrance).   It’s a nice place to kick back and eat your PB and J.  They’re supposed to charge you $6, but they might let a bicycle pass.  The water is free in any case.

IMG_4743After Grant the road surface goes back to flawless and the serpentining gets even better.  The road will get steadily curvier as you ascend until in the last miles before the observatory it’s practically comical.  There is a spot very near the turn-around where you can see below you ten distinct segments of Mr. Hamilton Rd. at once (counting the one you’re standing on).

After a second little descent drops down to a bridge, the rest of the ride is more of the same, now with frequent glimpses of your destination, the Observatory, on the summit ahead of you.


Lick Observatory, your destination, in the distance

The Observatory itself is fascinating, so definitely plan at least a couple of hours there when it reopens. There are exhibits on the old telescope and how it was built and transported up the mountain, the telescope itself (straight out of Jules Verne), a charming inner courtyard where I love to sit and breathe the negative ions from the water fountain, and a gift shop.

The Observatory is very bike-friendly.  Continue on through the parking lot around to the right and you’ll find a bike rack, a sign reading “Please remove or cover cleats,” and a door to good bathrooms, a Coke machine, and a drinking fountain.   The fountain even has a water-bottle-friendly spout.  Go straight through the second door to get to the courtyard.

The Observatory (when it reopens) will have irregular hours if the past is any indication, so check visiting hours if you’re interested, but the restrooms, drinking fountain, and Coke machine should be open 8-5 daily.

The ride back varies from good to great.  The first couple of miles are too twisty to be unqualifiedly joyful.  You’re on your brakes most of the time, often hard on them, you’ll do a lot of 9-mph corners, and you can’t sustain any rhythm.  Then the road straightens out just a little, and that makes all the difference—it’s excellent for the three miles to the bridge.  After the short climb, the descent to Grant Park is my favorite descending section on the route—the curves are large enough and sweeping enough that you can sustain a lot of speed, and gentle touches on the brakes will suffice.

Much of the descending is high drama thanks to two factors: 1) on your L you have what seems like the entire world open before you, enormous open spaces and precipitous drop-offs, and 2) Santa Clara County has apparently decided it has better things to do with its money than install guard rails, because there are none.  One missed right-hander and you’re dead.  Mount Diablo and Mt. Tam have no drop-offs worth mentioning and thus can’t compare in sheer fear factor.

Which of the three iconic rides has the best descending?  I can’t say—they’re each outstanding in their own way.

After the moderately long climb out of Grant, the serpentining continues for a mile or so, and it’s actually some of the best descending on the route, because you’re crossing the top of the ridge so the pitch is gentler and you can attack it harder.  The last miles are tamer, straighter, but still good, and on any other ride they would be praise-worthy, but by then the descending bar has been raised so high they feel routine.

By the way, both climbs on the return are more than mere bumps, but they’re mellow and nothing to fear, even with tired legs.

Shortening the route: Start at Grant Park.

Adding miles: The Sierra Road ride is a stone’s throw to your north.  A short car trip to the south is Metcalf Rd., made famous in the 2013 Tour of California as the last 3K of the time trial.  It’s a lot like Sierra, a seriously steep climb people ride for the glory of it.

A lot of people who ride Mt. Hamilton do it as part of a long semi-loop: ride BART to Berryessa, ride to Mt. Hamilton Rd. and up to the Observatory, then just keep on going, down the back side of the mountain to Mines Rd. and the Dublin BART station.  This route is frequently ridden in the opposite direction.  Either route takes you right past the turn-around spot of our Del Puerto Canyon Road ride.  This is the dry side of the mountain, so the landscape is stark.

Afterthoughts: East of San Jose in summer is HOT, and, while you are riding past oaks, they don’t canopy the road, so it’s an exposed ride.  Try to avoid summer afternoons, carry a lot of water and food, and refill your water bottles at Grant and the observatory.

Looking back on seven or eight sections of our road from near the top of the ride, with San Jose and the South Bay in the distance

20 thoughts on “Mt. Hamilton

  1. corvetti

    This was the most concentrated uphill ride we’ve done yet, but the grade is never that steep, so it’s completely doable. Cool observatory at the top, with endless views. Try not to do this midday when it’s super hot out, though, because there are large stretches where there isn’t much tree covering. That said, we did it mid-day when it was 100 degrees out, and we still had a great time.

    1. patcresmar

      As usual, excellent description. Just one thing to add–it can get pretty cold at the top, even if it’s warm below. Thank goodness for the gift shop, which sells hot cocoa!

  2. Nibbles

    You can certainly ride up to the summit, BUT, you need to take the quimby road detour.—quimby-road-west.html

    Quimby is a pretty but seriously steep climb (steeper than Sierra, for sure) that filters out many a casual would-be hamilton rider.

    You ascend to the summit of quimby, then descend a mile or so (600 ft) to grant park. The rest of the ride is the same as described by Jay.

    1. Jack Rawlins Post author

      Mapmyride indicates it’s 3.3 miles, 1750 ft and steady, which is only a little over 10%. If that’s true, it can’t compare with Sierra Road.

  3. Maurizio

    Yes, just did Quimby, probably average 10% climb, max 20%. definitely not for the casual rider. However, once you know it it’s fun in a challenging way

  4. Ralph

    Great description. I’d add that the west side’s descent is perfect… if you’re into the terrifying, slot-car, tight cornered, smooth road kind.

    One of the better Bay Area rides is going the other way. Start on Mines Rd and go over the east side. I generally do it once or twice a year. I’ll either get a drop-off or take BART to Dublin. Then you can grab BART back or Caltrain if you are based on the west side of the bay (my case).

    Note: Water is an issue on the Mines side. There are only two reliable water opportunities. A fire station (47625 Mines Rd, Livermore, CA 94550) just before you get to the the 130 junction. At 130 junction there is a little country do-drop-inn restaurant/bar called “The Junction” (47300 Mines Rd, Livermore, CA 94550). Highly recommended. Good food. Nice people. You’ll need food and water.

    It’s a big day for anyone. It could be a painful one for most people.

  5. Nibbles

    Last Sunday a buddy and I got dropped off at Patterson and rode back to San Jose. Del Puerto Rd. is a delight, and the miles between the Junction (which as our luck would have it was closed) to the base of the east side climb up Mt. Hamilton are about as remote as anything I’ve ever ridden. In fact, a lot of it reminded me of the eastern part of Nacimiento road.
    The east-side climb is punishing, to say the least. 4.6 miles averaging 9% isn’t terrible per se, but hurts a lot more after 40 long, mostly uphill miles.
    IMHO the descent from the Mt. Hamilton observatory to the bridge is without peer anywhere in the Bay Area.
    It’s a long day, but you end knowing you traversed the entire Diablo range, and that’s a neat accomplishment.

  6. Gman

    I ride it almost exclusively at night, several nights a week, sometimes timing it to get to the top just as the sun is coming over the Sierras and sometimes leaving around midnight when the traffic below Grant Ranch quiets down. Either way, I have the whole mountain to myself, except for the occasional mountain lion or pack of wild boars. Often tarantulas will be out on the road. You do have to be alert because animals, and the odd driver, don’t expect you at that time. I’ve almost crashed into a huge cow-sized boar while descending, by the gate, and once came across a full-grown lion just sitting in the middle of the road. When you’re all alone it can be a little spooky. But nothing beats it.

    1. Jack Rawlins Post author

      Not sure you aren’t pulling my leg, but OK. I’d guess that most of the rides in Bestrides are pretty traffic-free at 3 AM. I’m not sure it’s the Sierras the sun is coming up over, but they’re somewhere to the east for sure.

      1. Gman

        I’m assuming it’s the Sierras. On a clear day you can pick out Half Dome from that last left-hand corner just below the big telescope, when you first get a good view to the east.

        1. JP

          Gman, your description of riding that route in the dead of night is amazing to me. What an adventure. Are you commuting to a job in the Bay Area when you do that?

  7. Jack Rawlins Post author

    Yes. The area around the beginning of Mt. Hamilton Road is solid residential, but parking isn’t restricted and you can find curbside parking in front of someone’s house easily. See Tom B.’s comment below.

  8. Lachlan Smith

    Any thoughts on the safest way to ride from the Guadalupe River Trail to Mt Hamilton Rd?

    1. Jack Rawlins Post author

      No. All options seem thoroughly unpleasant. One word of caution: if you take a route that sends you up Quimby, you’re looking at one of the fiercest pitches in the Bay Area.

    2. Tim Wallace

      Make your way over to San Antonio Street and head east. It’s a relatively quiet residential. At the 680 overcrossing there is one crappy half mile on Capitol Expwy. Then take a left at the first light and you can take quiet back streets over to Alum Rock Ave, where it starts to climb up to Mt Hamilton Road. Not the best riding, but the best in that very bike-unfriendly area.

  9. Chris Doyle

    Road work and repaving are completed as of May 2021. The new surface is wonderful, especially the descent from the top, which previously had some sketchy bumps and things. All that has been fixed. It’s smooth sailing. Heaven!

  10. David

    Did the ride today (9/26/21), adding the east-side descent/climb. Even though Lick Observatory is closed, there is water at the entrance before the gate. The new pavement is awesome, especially when descending—probably one of the best descents in the East Bay now. The east side, down toward Livermore, is not repaved. It is much steeper, and a bit technical, but not terrible to go down. A challenging climb with extended ramps of 10-11%.


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