Guanella Pass Bike Climb - PJAMM Cycling

Guanella Pass


Peaceful and challenging climb out of Georgetown CO ending just west of Mt. Evans

Explore this Climb

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Climb Summary

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. 

This scenic climb begins at the northern end of the very quaint small historic mining town of Georgetown, population 1,034.

Begin the climb at the southern edge of Georgetown.

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


Our 2015 ride was marred a bit by the recent oiling of the roadway which, along with a headwind and steep grade in parts made for a rather challenging climb (the 2020 ride benefitted from the 2015 new roadway, however 😊

It is a beautiful climb with minimal vehicular traffic.

On our August 2015 and August 2020 visits to Guanella Pass there were plentiful wildflowers along the road and the views back down the canyon from almost the start on through the summit were spectacular, particularly at the summit.

 The pass is not really marked, although 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 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; but, no summit sign 😪

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.