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Bitterbrush - Upper Section

Intermediate Intermediate
 4.2 (50)
  1. Areas
  2. CO
  3. …Front Range
  4. …Lyons
  5. Hall Ranch
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“The top part of Bitterbrush is a gradual singletrack climb up to Nelson Loop. ”

Michael Ahnemann
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1.4

Miles

2.3

KM
Singletrack

6,388' 1,947 m

High

6,056' 1,846 m

Low

332' 101 m

Up

11' 3 m

Down

5%

Avg Grade (3°)

8%

Max Grade (5°)

Dogs No Dogs

E-Bikes Unknown

Description

This trail section starts from the top of either Antelope (easier way up) or Bitterbrush - Lower Section (more difficult way up) and leads to the Nelson Loop up top.

It's a mostly smooth, gradual climb - just follow the trail up.

On the way down, watch for other riders, hikers, and horseback riders climbing up. There's often heavy traffic on this trail.

Contacts

Local Club: Boulder Mountainbike Alliance

Nov 17, 2025: Trail Update: South St Vrain

Nov 14, 2025: Another Step Closer to new Betasso Connector

Oct 24, 2025: Boulder County Moves One Step Closer to a Safer Boulder-to-Betasso Connection

Land Manager: Boulder County, CO - Parks and Open Space

Shared By:

Michael Ahnemann
Full Details

Trail Ratings

  4.2 from 50 votes

#3

in Hall Ranch

#234

Overall
  4.2 from 50 votes
5 Star
34%
4 Star
52%
3 Star
14%
2 Star
0%
1 Star
0%
Trail Rankings

#3

in Hall Ranch

#91

in Colorado

#234

Overall
14 Views Last Month
2,627 Since Nov 20, 2012
Intermediate Intermediate
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Photos

Dropping down the back side of Hall Ranch, just after the Antelope connector.
Oct 31, 2016 near Lyons, CO
HALL RANCH | JULY 2018
Nov 8, 2018 near Lyons, CO
Flat out run from summit of Nelson Loop, down upper Bitterbrush and down Antelope to trailhead.
Aug 2, 2017 near Lyons, CO
At the junction with Nelson Loop. Starting left (doing the loop clockwise) is gives you a better descent, but it's open both ways.
Nov 22, 2012 near Lyons, CO
Railing corners on upper Bitterbrush at Hall Ranch.
Nov 16, 2015 near Lyons, CO
Going up the Upper Section (not yet at Nelson) and looking back. This was a fun trail, challening trail for me -- as an Beginner/Moderate rider.
Aug 26, 2018 near Lyons, CO

0 Comments

Weather

Current Trail Conditions

All Clear 18 days ago
Add Your Check-In

Check-Ins

May 10, 2025
Sarah M. F.
1.4mi — 0h 15m
Jun 12, 2023
Hunter Rone
Fun!
Apr 16, 2023
Fehim Hasecic
Jun 8, 2021
Steven Chepke
Unknown time, fun run, 3/5, open field flowing run. The fun section I was capable of for my second ride ever. 1.4mi
Nov 17, 2019
Krys Contreras
1.4mi
Aug 26, 2019
Renae Sohlden
May 19, 2019
Private User
Oct 3, 2018
Patrick Burns
Not all the corners flow well, and that is a good thing. A bunch of awkward righthanders really force you to try hard.

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