Cottonwood Pass Bike Climb - PJAMM Cycling

Cottonwood Pass


One of several Colorado climbs ending at the Continental Divide.

Page Contributor(s): Bruce Hamilton/Stacy Topping

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Climb Summary

Bike climb to Cottonwood Pass - Continental Divide sign.

Cycling Cottonwood Pass - one of US 100 Bike Climbs that reach the Continental Divide.

Ride 19.2 miles gaining 4,320’ to elevation 12,131 at 4.1% average grade.

Cottonwood Pass (East) is one of only 6 climbs in the U.S. that top out above 12,000' (5 of those 6 are in Colorado - the Himalayas of North America).   This is an up-and-back ride as the back side of the pass is not paved.  This is also one of only 3 of  the 13 Colorado Top 100 U.S. Climbs that ends at the Continental Divide  (Independence Pass and Wolf Creek Pass are the other two).

Cottonwood Pass is in the Sawatch Mountains Range of central Colorado and is part of the Rocky Mountains.  8 of the 20 highest peaks in the Rocky Mountains are in the Sawatch Mountains.[1]

Climbing Cottonwood Pass by bike - PJAMM Stacy Topping at continental divide sign with bike

This spectacular climb begins at the western edge of yet another quaint Colorado town, Buena Vista.  We actually are travelling a County Road on this one (Chaffee County road 306), beginning at elevation 8,016 and riding to an oxygen sucking 12,127’.  

Bicycle ride up Cottonwood Pass  - Hwy sign,

Buena Vista (pop. 2,806 in 2017; ele 7,965’)

Cycling Cottonwood Pass  - roadway sign, highway and mountains

Bike climb up Cottonwood Pass  - highway 306; San Isabel National Forest sign.

Enter San Isabel National Forest at mile 4.3 (est. 1902 by Teddy Roosevelt; 1,120,233 acres).

As we climb up through a series of gulches (Short, Deadman’s, Harris Gulch and Denny Gulches) for 4 miles from miles 7 to 11, we are surrounded by thick forest (many cottonwoods – go figure!) and follow and often hear the soothing flow of Cottonwood Creek.  The views of forest giving way to barren steep mountainsides is dramatic along the majority of the climb.  At about 17 ½ miles we climb  above the tree line and see a mighty switchback that leads to the pass summit and Continental Divide about a mile up the mountain.  

Cottonwood Pass in spring.

      Cycling Cottonwood Pass  - roadway

The views at the top of the pass are absolutely breathtaking and make the climb a must for those cyclists in search of challenging climbs that include spectacular views

Climbing Cottonwood Pass  by bike; hairpin curve, hwy 306 and speed limit sign

Hairpin just before the pass.

    Biking Cottonwood Pass - Giant Loop just below the pass

View south from the pass.

Bicycle climb of Cottonwood Pass - lake at the pass

View north down the backside (dirt road) of Cottonwood Pass.

Bicycling Cottonwood Pass - view past flowers to mountains at the top

As of 2019, the east (back) side of the pass is not open.

Ken Read (CAN Olympic Team 1976, 1980; 5 World Cup wins), Canmore, Alberta, Canada, writes of this climb on August 4, 2019:  “Rode the pass today - newly paved right to the pass & they are preparing to pave the west approach. Lines most of the way up, with a white shoulder line as well which helps for the few cars and trucks - the few there are.”

Continental Divide Top 100 US Bike Climbs

cycling Independence Pass CO - Continental Divide Sign

Wolf Creek Pass (top photo) - southwest CO (Pagosa Springs)

Independence Pass - central CO (Aspen)
Cottonwood Pass - central CO (Buena Vista)

Trail Ridge - stops 9 miles short of the Divide.

Steepest ¼ mile  starts at mile 12.1 (9.1%) and mile at 11.8 (7.4%)

From PJAMM contributor Brett Dixon, CO for the back side of the pass:  

The west side of Cottonwood Pass is dirt all the way down. It is often in great shape for climbing this time of year, but the descent demands attention on skinny tires.”  Brett also provides a summary of his experience with Cottonwood Pass:

“Cottonwood Pass, also known as County Road 306 from the east and County Road 209 from the west, is a gem of the Sawatch Range. The west side of the pass is hard-packed dirt, which deters many road cyclists. However, this also cuts down on traffic from the east side, which is graced with generally excellent pavement. The climb up the east side covers 19.2 miles from Buena Vista with approximately 4,200 feet of elevation gain. The high point stands at 12,126 feet, which can be problematic for visiting cyclists who do not have time to acclimate to high altitude.

The starting point for this route is at the US 24/CR 306 traffic light in Buena Vista. You get out of the town pretty quickly and into some open terrain that is often accompanied by a headwind. The first half of the climb is relatively easy, with an average grade in the low single digits, and provides a great opportunity to warm up. The climbing really starts 12 miles in at the Denny Creek Trailhead with a wall of double-digit grades for less than one mile. The grades back off a bit after this section and remain fairly constant for the remainder of the climb. The final four miles are marked with a few curves and switchbacks. Your efforts are rewarded with a spectacular view at the top.

The low traffic, smooth surface, and long stretches of straight road make this a special route for those who enjoy turning around and descending after the climb. It is easy to sustain speeds between 40 and 50 mph without much effort and even push 60 mph at the steepest points. Professional racers flirt with 70 mph around the Denny Creek Trailhead during the USA Pro Challenge. Exercise caution on the way down as you are likely to gain more speed than usual on the return to Buena Vista.

This is a 2 lane road the entire climb, but, other than a fairly congested first couple miles, traffic is light and travels at a reasonable speed.  There are no bike lanes or shoulders (but many turnouts -irrelevant for the most part to we cyclists) yet this feels to be a comfortable and safe climb.  

Cottonwood Pass is 94 miles from Colorado Springs and 120 miles from Denver.  This is such an exceptional climb that it is surely worth traveling to for a day trip, or an overnight in Buena Vista.

An excellent summary of the climb, along with photos is found at posted by the Colorado Guy.