Mt. Wilson Bike Climb - PJAMM Cycling

18.5 mi
4,596 ft
4.5 %


Page Contributor(s): Marshall Yale, LA


Ride your bike to Mt. Wilson Observatory - one of the longer and more challenging bicycle climbs in Southern California. Great views of the San Gabriel Mtns, Mt. Baldy peak, and downtown LA from the summit make this one of the most popular climbs in the LA area. 
The grade on this climb is fairly consistent, remaining between 4-7% for the majority of the ride. Only a few brief periods ever reach double digits, but none of which long enough to be captured on our gradient profile.  The steepest section is the beginning of the climb, from Foothills Blvd to the La Cañada country club. There is a 1.6 mile -2% descent beginning at mile 8.3.  Eliminating the descent on this climb raises the grade from 4.5% to 5.4%.
The road is in excellent condition (as of 2021)

Traffic over the first several miles on Highway 2 can be moderate and fast moving, but there is often a 3-foot shoulder and frequent pullouts. People do tend to drive a bit recklessly on this road, so if you're at all traffic sensitive, we recommend doing this on a weekday or starting at the Red Box Picnic Area (this shortens the climb to 4.4 miles at 4.6% grade) and the turnoff for Mt. Wilson Road, where there is minimal traffic. 

We parked on a parallel side street at the start of the climb for our 2 trips up Mt. Wilson.  MapStreet View
There is a public water fountain at the Clear Creek Fire Station (at the intersection at mile 9.5) as well as restrooms and water at Red Box Picnic Area (mile 14.1). Snacks, sandwiches, (and root beer floats!) can be found at the Cosmic Cafe at Mt. Wilson Observatory (open from 10am-5pm on weekends) just past the finish of the climb. Check the Facebook Page for details before your climb if you are interested in a meal there at the end of your climb. 

As with all climbs to much higher altitude than your starting location (here 4,000' change) be sure to check the PJAMM Weather Tool for weather conditions at the finish around the time you intend to arrive and pack accordingly.  Even though winter weather may be perfect at the start in sunny southern California, there may be snow at the top!
Before heading out on any cycling adventure check out our Things to Bring on a Cycling Trip and use our interactive check list to ensure you don't forget anything.
Check out our full ride suggestions in the Full Summary.

Mt. Wilson is not far from some of the great Santa Monica Mountains bike climb (Santa Monica Mountains).  It is only 15 miles from one of our favorite Southern California bike climbs (Hollywood Sign) and a great way to get around the San Gabriel Mountains.  

Consider visiting the Mt. Wilson Observatory at the finish of the climb - see Full Summary for more details (Google Map + Reviews).  You can find several hotel options in nearby Pasadena.  Or look for house and villa rentals in the area.



Difficulty: Challenging



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San Gabriel Mountains
United States (CA)
43 POIs


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Sep 25, 2023
difficulty: Challenging
scenery: 5
traffic: 2
road: 4
Sep 25, 2023
scenery: 5
traffic: 2
road: 4
A must-do climb for cyclists in the L.A. area. Not a hard climb; it is very consistent with the steepest section in the first 2-3 miles and the route flattens out approaching Clear Creek at 9 miles. Just past Clear Creek is a 1/2 mile descent before the climbing resumes to the turn on Mount Wilson Rd at Red Box. Both Clear Creek and Red Box have water available. The scenery is spectacular once you pass Clear Creek, especially once you get into the last 4 miles on Mt. Wilson Rd. This ride is best done on a weekday with an early start (no later than 0800) as the road is used by motorists and motorcyclists testing their driving skills on the twisty roads. The road surface is surprisingly good, although on the descent you can get some "chatter" and wheel skip at high speeds. Aside from the turnouts/view points there is little to no shoulder and you can encounter sand/gravel, rocks, and other debris (acorns were abundant on Mt Wilson Rd).
Jan 6, 2022
difficulty: Challenging
scenery: 4
traffic: 3
road: 3
Jan 6, 2022
scenery: 4
traffic: 3
road: 3
Went up for the first time yesterday (01052022). Must have been timing (8am start) but traffic was pretty mild, despite the snow covered San Gabriel’s. Never felt unsafe on the ascent, only honked at once for being on the left side of the white line. Once you pass Clear Creek and the descent the climb really turns gorgeous. Mt. Wilson Road is still closed to vehicles but the gate was half closed. Lots of mudslide debris from our recent storms and patches of ice (since it is on the north side of the mountain the road doesn’t get much sun). The observatory gate was closed but still got to the summit no trouble. The descent was fine, again not a lot of traffic and most cars gave me space. A radar taillight is a good thing for piece of mind on any ride but it pays for itself when climbing or descending. 10/10 would do again, but would still probably avoid doing it on the weekends.
Aug 15, 2021
difficulty: Challenging
scenery: 4
traffic: 2
road: 4
Aug 15, 2021
scenery: 4
traffic: 2
road: 4
Ugly traffic, even early on a Saturday in July (2021) - car clubs and motorcycles ripping it up the road, and not much of a shoulder to cycle on. There is a water stop at Red Box Trailhead, which is where things turn absolutely beautiful.
Jun 20, 2021
difficulty: Challenging
scenery: 3
traffic: 3
road: 5
Jun 20, 2021
scenery: 3
traffic: 3
road: 5
If you don’t like traffic/ motorcycles/ race cars go early! I started at 7AM on Saturday and the traffic was definitely manageable on Highway 2. The descent later in the day was much less enjoyable however. Even though you are going just as fast as the cars they still seem to want to get around you. The first two miles are the steepest and then the climb is super consistent at about 5% except for one minor flat section around mile 9 and two small downhills in the last 4 miles. Highly recommend this climb, just make sure you bring enough water as there is nowhere to get water except maybe the cafe at the top of the observatory but it doesn’t open until 10AM.
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Cycling Mt. Wilson -- a top Southern California bike climb beginning in La Cańada Flintridge

Ride 18.1 miles gaining 5,376’ to elevation 5,658 at 4.5% average grade.

Climb summary by PJAMM’s John Johnson.

Beginning in Flintridge, we ride through a residential area for 1.8 miles to the point where road narrows to two lanes and becomes more rural and scenic.  While this is a great climb from mile 9.2 on[1], the first nine miles are unpleasant due to a narrow shoulder and heavy traffic that travels at highway speeds (60mph+).  At the junction of Highway 2 and County Route N3, we continue on Highway 2 for another 4.5 miles to Mt Wilson Road.  The grade on this route is fairly steady, in the 4-6% range and rarely exceeding 7%.

Road sign at beginning of Mt. Wilson climb by bike     

Start of ride.

 Roadway sign on Hwy 2 during bike climb

First 13.8 miles of this bicycle climb are on Highway 2.

The most scenic and less nerve-wracking (i.e., lighter traffic) part of this climb is from mile 9 to the radio towers at the top at mile 18.  We turn off of Highway 2 at mile 13.8 and it is approximately four miles to the television towers at the top of the climb.

Angeles National Forest road sign on Hwy 2 during bicycle ride to Mt. Wilson

Enter Angeles National Forest at mile 2.3,

Established 1908 by Teddy Roosevelt; 655,387 acres.


Turn onto Mt. Wilson-Red Box Road at mile 13.7

4.3 miles at 4.6% to TV Towers and end of bike climb.

The road from Highway 2 to the top is very scenic and along a portion of the road that has sheer drop-offs just over a short rock barrier.  There are excellent views of San Gabriel Peak to the southeast for the first mile, we pass through Eaton Saddle at mile 16.2, and for the next couple of miles have great views of Highway 2 and the San Gabriel Mountains to the northeast as we continue up Mt. Wilson road.   



Mt. Wilson Red Box Road -- Wilson Observatory in photo middle.

This climb ends at the KCAL TV towers at mile 18.  The Mt. Wilson Observatory is another half mile past our end point, but at a lower elevation.

Just about to the top.

Excellent views of Los Angeles from the top of this climb.

Before heading out to climb Mt. Wilson, be sure to rely on our list of Things to Bring on a Cycling Trip, and use our interactive checklist to ensure you don't forget anything.


The Mount Wilson observatory was founded in 1904 by solar astronomer George Ellory Hale and his team.  Hale acted as director of the observatory until his retirement in 1923.  An informative article about Hale’s life and the beginnings of the Mount Wilson observatory can be found here.  Hale had an accomplished scientific life, and is best known for his discovery of magnetic fields in sunspots, and in addition to founding Mount Wilson, he also founded the Yerkes Observatory, Palomar Observatory, and the Hale Solar Laboratory.  More information on Hale can also be found here.

We arrived too early to visit the observatory.

Hours as of August 2019 were 10 a.m. to 5 p.m.

Einstein visits the observatory in 1931.

Evidence supporting the theory of relativity was gathered here.


Inside the observatory


Today, the observatory is open for free tours from 10 a.m. to 5 p.m. and is home to two historical telescopes:  The 100” Hooker telescope which was the largest aperture telescope in the world from 1917 to 1949, and the original 60” telescope which was the largest in the world when it was completed in 1908. The first telescope on Mt. Wilson was built in 1904 and funded by the Carnegie Institution of Washington.

Due to the inversion layer that traps smog over Los Angeles, at 5,710’, Mount Wilson has the steadiest air in North America.  Thank you LA smog...I guess???

Inversion layer at work.

The brown line just below the blue in the center of the photo is smog.

This is the alternate route to Dawson Saddle (Map) which avoids the six miles of closed Highway 39 along the “main” Dawson Saddle climb, but is also much longer (45 miles to the Saddle, making it just over twice the length of the more traditional route) and includes a little over 2,000’ of descent -- so, it is not a true Top Climb, by Fiets standards, anyway.  We also must travel along the busy section of Highway 2 for 10 miles.

Roadway Surface and Traffic Report:  Highway 2 has a very narrow bike lane which is often merely a white line with 6” of pavement and loose gravel to the right.  Traffic is heavy and fast-moving for the first 9 miles of the climb.  For those who wish to avoid highway traffic, do not undertake this climb, or begin at mile 9.2, after the junction of Highway 2 and County Route 3.

That’s a wrap!

[1] Most of the traffic along the first stretch of Highway 2 turns onto Angeles Forest Highway (County Route N3) at the 9.2 mile mark, this is the route to Palmdale and a connector to Highway 14.

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