Guanella Pass Bike Climb - PJAMM Cycling

10.8 mi
3,308 ft
5.4 %


Page Contributor(s): Bruce Hamilton, La Quinta, CA, USA; Stacy Topping, Tacoma, WA, USA


Cycling Guanella Pass - this is a popular Colorado bike climb beginning in Georgetown and ending at 11,657'.  We ride through a canyon much of the climb and pass hydroelectric reservoirs on our way to the top.  During spring and summer you will see many colorful wildflowers growing near the roadway. 
5.4% average grade (6.4% climb only; there are five short descents on the route (longest is 0.25 miles at -5.8%). 37% of the climb is at 0-5% and 39% at 5-10%. The steepest quarter-mile on this ride is 10.9% and steepest mile 8.8%.

See more details and tools regarding this climb's grade via the “Profile Tool” button.
Roadway:  Excellent. 

Traffic:  Mild.

Parking:  There is parking on the way into Georgetown on the side of the road and a couple public parking lots in town, the closest is here:  Map Street View.  This Google Map - Parking map may also be of assistance. 
There is no water or food along the route. 

You will finish this climb at high elevation so consult the PJAMM "Full Forecast" feature for the time you expect to arrive at the finish to assess what clothing to bring on your ride.
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.
This climb can be included as part of your Denver-based bike climbs (PJAMM page - Denver, CO - 45 miles) or, if you prefer, as part of your Boulder-based bike climbs (PJAMM page - Boulder, CO - 56 miles).  Consider staying in Georgetown which is a very charming historic mining town (Google things to do in Georgetown).  Denver, Boulder, and Georgetown all have great options for vacation rental accommodations as well.  Give the Loop Railroad a chance - it is very scenic and fun - (Google Maps + Reviews). 



Difficulty: Strenuous



Check out PJAMM Adventure's prepackaged (self-guided) cycling trips. They will help you plan, document and conquer your next adventure.
Browse all of our prepackaged trips and find your next adventure!
Colorado: Front Range
United States (CO)
46 POIs
RMNP: Trail Ridge Road
United States (CO)
33 POIs


No Climbs Found


Let us know what you thought of this climb. Signup for our FREE membership to write a review or post a comment.
Already have an account?

Jul 15, 2023
difficulty: Challenging
scenery: 5
traffic: 3
road: 4
Jul 15, 2023
scenery: 5
traffic: 3
road: 4
My new 2nd hardest climb (#1 is Turini to La Forca) and it was very much split up into 3 different parts: 1. The starting 3rd: this hits you at the start and even as you just start the climb, the altitude is already kicking in. There are some bike-friendly swichbacks on this part. There was a lot of weekend traffic/tourists here, but it thins up as you go up the climb. 2. The second 3rd: this part is very flat, but there are some 200-ish meter ramps, but you usually have a lot of momentum to glide up most of the ramps. There are some downhills that you can take advantage on for those ramps. Also, there are horseflies everywhere on this section. 3. The final 3rd: This is the steepest part. I would say it starts with about 5km to go, but it really gets steep at 4km. You go above treeline, and you get closer to the top. There are a couple more switchbacks until you see the "Welcome to Guanella Summit" sign. After that, you can see the crest, and the climb ends there.
Jul 12, 2023
difficulty: Extreme
scenery: 4
traffic: 5
road: 4
Jul 12, 2023
scenery: 4
traffic: 5
road: 4
The hardest ride I’ve ever done
Jun 15, 2023
difficulty: Strenuous
scenery: 4
traffic: 5
road: 5
Jun 15, 2023
scenery: 4
traffic: 5
road: 5
One of the best mountain roads in all of CO
Route Data
S.G. (%)
Segment Data

Climb Profile Not Found

Climbing Guanella Pass by bike - a challenging and peaceful bike climb.

Ride 10.8 miles gaining 3,606’ to elevation 11,657 at 5.4% average grade. 

Climb summary by PJAMM’s John Johnson.

This scenic climb begins at the northern end of the very quaint small historic mining town of Georgetown, population 1,034. And, as often as not, if there’s wind, you’ll have a tail wind helping you up the mountain.

Begin the climb at the southern edge of Georgetown.

Before heading out to cycle Guanella Pass, 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.

First viewpoint is in the middle of hairpin 2 (½ mile up from the start)

Wonderful view of Georgetown from here.

Viewpoint #2 is located at mile 2.5 at the second hairpin of the second set of hairpins on the climb.

From this point we have a nice view of the canyon and Georgetown Reservoir that we ride by 8/10’s mile earlier.

The climb is broken into 3 parts:  hard, easy, hard – 1st 3 ½ miles at 6.7% gaining 1,303’, the middle mild segment (5 miles at 2.9%) and the final 2.3 mile switchback section at 7.4%.    

We ride through a canyon for most of the climb, following the South Clear Creek River for nearly the entire route, although the creek is not always in view.  This is a hydroelectric area and we pass by 2 lakes, a reservoir and a major power station during the first 5 ½ miles.

Green Lake and Green Lake Lodge - mile 3.5

Cabin Creek Hydroelectric Reservoir at mile 5.5


On our August 2015 and August 2020 visits to Guanella Pass there were plentiful wildflowers along the road and t

It is a beautiful climb with minimal vehicular traffic.

The views back down the canyon from almost the start on through the summit were spectacular, particularly at the summit.

The pass is marked with a summit sign (but not altitude) and there is a brass plate commemorating the Pass namesake, Paul Guanella, at the road’s high point.  Note that the north (Grant side) of the pass is closed from 4-15-14 to 10-31-15 according to the sign we encountered along the southern ascent (photo).  Once open, the 46 miles Georgetown to Grant out and back should be a superb ride/climb (46 miles / 6,463’ climbing) - Map.  We would appreciate a report for anyone who does, or has done, the out-and-back.

Plaque at the summit.

Sign near the summit.

Thank you Bruce Hamilton and Stacy Topping.

This is a beautiful climb that is well worth the effort if you are anywhere in the area.  It would also be worth a trip just to visit Georgetown (stay overnight if you can) and climb the pass.  Georgetown was established in 1859 in relation to the Pikes Peak gold rush.  The town has a population of 1,034 is at elevation 8,530’ and has several blocks of restored and well maintained vintage century-plus mining-era buildings and is quite charming (see video of town).  For those out of area, there is some lodging in Georgetown itself and Idaho Springs is only 12 miles east on Interstate 70.


Aerial view of climb finish looking north towards Georgetown, down the canyon we just rode up.

The entire Guanella Pass bicycle climb is in Arapaho and Roosevelt National Forests (established, like so many other National Parks and Forests, by Teddy Roosevelt in 1908; 723,744 acres).  

Very tame rocky mountain bighorn sheep a few miles up our climb in August, 2020.

This seems to be a fairly popular cycling route as we saw several cyclists doing the climb on the weekdays we were there in 2015 and 2020 and there were 850 riders who had downloaded for the Guanella Pass Strava segment as of 8-6-15 and 2,074 as of 8-18-20.  

From our cleats-on-the-ground PJAMM collaborator in CO Matt Dupree (Thanks much Matt!):

The first thing you think about Guanella Pass is that it’s only 10.5 miles long and 3000’ of climb—it doesn’t sound too bad.  After all: 3000/(5280*10.4)= 5.4%

Not bad!

However, unlike other passes around the Front Range, Guanella is less efficiently graded, so it goes up and down more than you might be used to.  In fact there are pretty long stretches of flats in there, too.  I call this “climbing on credit,” you better enjoy those flats because you’re going to pay them back with interest later to get back to that 5.4% average.

The first mile demonstrates my point well.  The first mile climbs about 500’ over 4 switchbacks.  You can see them from Georgetown, and once you’re on them you’ll be amazed at how fast you’re climbing out of this nice little town.  (Coming down it you’ll feel like you should be looking for a runway.)  Soon the town disappears and after about 3.5 more miles you arrive at a sequence of reservoirs.  At each one you get a break from the relentless climb.  From mile 4 to about 6 you only climb a couple hundred feet.  This should seem ominous.

At about mile 8.5, you figure out after about 2000’ feet of climb that you have another 1000’ to go, and you’ve seen your last break.  This is where it gets steep, windy, and often cold.  At the top, after the last switchback, the road flattens out to the summit parking lot.  You are above treeline at 11650’ and can enjoy a great view of Mt Bierstadt.

The pass goes up a narrow canyon until the very top.  Because of that, the road and your view are very confined.  You won’t see storms coming up until it’s pretty much too late.  (I have had to shelter from hail and lightning at the hydroelectric plant, which was either the best or worst place to be in a thunderstorm, I don’t know.)  The wind gets channeled down (or up) the valley forcefully.  The road has nowhere to go, so there are a LOT of switchbacks, I counted 14.

The descent is fast but challenging because of the switchbacks.  The road is in great shape, so enjoy it.  You have an advantage over the cars here and can negotiate the turns much faster than they can; try to use your new superpower only for good.  You won’t be happy to see those lakes on the descent, because those little climbs sting when your legs are cold!

The road was paved in 2013, and is still kept up astonishingly well.  Even though the top is closed in winter, and even though it’s largely just recreational use, this road is very well-maintained and was just repaved in 2015.  Almost all the traffic stops at the top for hiking, then comes back down.  Because the road is mostly used to access campgrounds and other recreational stuff, the traffic pretty mellow and understanding.  It’s a courteous, accommodating place, even when I rode it Labor Day weekend and there were hundreds of cars parked all crazy at the summit.

Access to full Climb Summary requires a PJAMM Cycling PRO Membership!

It takes less than a minute to sign up & with your PRO membership you can:
  • Rate climbs, post comments and share your experiences on any of our climb pages
  • Create bucket lists of climbs & mark the dates you complete them
  • Weather data for all climbs - Start & Finish
  • Upload photos to your member page to customize your PJAMM Cycling experience
  • Utilize all of our interactive tools - Profile & Routes in Area
  • Download climb route .gpx files

Already have an account? LOG IN HERE