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South Sourdough (#835)

Intermediate/Difficult
 3.7 (33)
  1. Areas
  2. CO
  3. …Front Range
  4. Nederland
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“Sourdough Trail (South of Brainard Lake) ”

Alan Doak
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5.9

Miles

9.5

KM
Singletrack

10,274' 3,132 m

High

9,217' 2,809 m

Low

1,121' 342 m

Up

265' 81 m

Down

4%

Avg Grade (3°)

20%

Max Grade (12°)

Dogs Off-leash

E-Bikes Not Allowed

Description

From the Peak To Peak Highway, take the exit for the CU Alpine Research Center and park at the trailhead on the left. An outhouse is available at the parking lot.

The trail climbs up singletrack to the Brainard Lake road, which splits the southern and northern halves of the Sourdough Trail. The southern half of Sourdough is less technical than the northern half, and travels through splendid forest that rarely opens up enough for a vista.

This first two miles is a climb up fairly loose rocks and will keep you on your toes, though it's all rideable. The grade isn't too steep, but there's not much of a break until you get to a pretty bridge over a stream crossing at 2.5 miles.

The trail becomes smoother and faster at this point, but keeps climbing for a while with occasional views east through the trees. After about 3.5 miles, the trail becomes flatter and much faster to the end.

To return to the trailhead, either ride back on the trail or along the Peak To Peak Highway.

The trail is typically rideable (or mostly rideable) by the first week of June. Any sooner than that and you'll quite possibly be pushing through snow.

Contacts

Local Club: Boulder Mountainbike Alliance

Jan 11, 2023: Weigh in on Open Space Decisions and Policy on an Advisory Board

Dec 13, 2022: BMA’s Dec. 14 Comments Regarding the OSMP e-Bike Evaluation

Dec 12, 2022: E-Bikes in Boulder

Land Manager: USFS - Arapaho & Roosevelt National Forests Office

Shared By:

Alan Doak with improvements by Richard Hackett
Full Details

Trail Ratings

  3.7 from 33 votes

#1

in Nederland

#962

Overall
  3.7 from 33 votes
5 Star
21%
4 Star
36%
3 Star
30%
2 Star
12%
1 Star
0%
Trail Rankings

#1

in Nederland

#238

in Colorado

#962

Overall
22 Views Last Month
10,370 Since May 2, 2013
Intermediate/Difficult
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21%
15%
64%
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Photos

Perfect late summer conditions
Sep 20, 2021 near Nederland, CO
Winter means fresh tracks on the climb from Rainbow Lakes along South Sourdough.
Feb 18, 2017 near Nederland, CO
Peace Bridge in February has 3+ feet of snow!
Feb 23, 2017 near Nederland, CO
Bridge crossing and a good rest on the Sourdough Trail
Oct 15, 2014 near Nederland, CO
One of the few peeks through the trees.
Oct 15, 2014 near Nederland, CO

2 Comments

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Weather

Current Trail Conditions

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Check-Ins

Jul 3, 2022
Frank Selker
Aug 28, 2021
Andy Dog
A lovely ski trail. Would be sweet on a horse. No true expert moves but minimal flow due to many axehead sized rocks and roots. Not sure if I had fun 5.9mi — 1h 00m
Aug 5, 2020
Nicholas Horan
Over handlebars and injured 0.5mi — 0h 15m
Jul 4, 2020
Corbin Cowan
Aug 19, 2019
Jon Banks
A bit chunky but fun. Bikepacked from Ward to Ned
Jul 11, 2019
Paul Billings
Feb 10, 2019
s Pk
out & back climb 5.2mi
Sep 9, 2018
Austin West
11.6mi

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