64.1 miles
6,122 ft
-6,134 ft
1 mile
High Point


Want an epic ride? Well we've got one for you We've linked trails to get you from uptown Boulder to Lyons (Oskar Blues) and back. All told it's about 50 miles of some of the finest front country pushing you can do in Colorado. You'll get everything from amazing landscapes to solitude, to death defying rock gardens to some great beer all in one butt kicking ride!

Conceived by Boulder Monuntainbike Alliance member Kevin Bracy Knight, this is the biggest way to ride our part of the Front Range! The first recorded person to complete the ride is Dan Hickenstein in October 2011. He noted that we sandbagged the length just a bit - turns out it's about 66 miles round trip! He did it in 8hrs and 40min, so go get it!

The Route:
1) Foothills Trail/Eagle Trail/Lefthand Trail
Starting at 4th and Kalmia in Boulder, hit the Foothills Trail. Sitting high on your seat, pedal past the mere mortals as you cruise past Wonderland Lake and the sadly empty prairie dog town near Lee Hill Rd. Keep on moving with Twix under Hwy 36.

When the trail dead ends into a parking lot, turn left onto Old North Broadway. Cruise on this until it too dead ends into a gate. This is the Eagle Trail. Continue on this trail until you drop down off the mesa and take a hard left onto the Sage Trail. Follow Sage to the parking lot, where you'll go through a couple of gates (get used to gates, you've got a billion more here - we know, we're going to work on a solution with the Open Space folks soon) and you'll get onto the Left Hand Trail. Follow this until it too deadends (into Neva Rd.)

And here, you have a choice. When this ride was conceived, Joder Ranch did not connect to Lefthand Canyon.

2a) The Masochistic Option
So for an "easier" ride, continue to step 2b) For a bonus climb, turn west on Neva Rd, north on Hwy 36, then careful cross the highway to Joder Ranch. After you make it up the very steep Jeep road and down the fun singletrack, turn right on Olde Stage Rd, then another right on Lefthand Canyon Dr, and then a left on Geer Canyon Rd.

2b) The Boring Road Part
Well, it's not super boring. At least you get to ride on dirt quite a bit. Cross Neva Rd. and get directly back onto dirt on 39th St. This get's a bit funky here so hold on to your horses. 39th dead ends into Nimbus Rd. Go Right! Nimbus turns left into N. 41st st. Groove on down the road. That road does an "S-bend" to the left and becomes 39th St. again. On your left about 1/4 mile on down, you'll see Plateau Rd. which is a left turn for you. This dumps you onto Hwy 36 about 150 feet South of Lefthand Canyon Dr. Head on up Lefthand. From here, it's about 1/3 mile up the road to Geer Canyon Rd. which is a right turn and has a sign for Heil Valley Ranch. Turn here and head up to the Heil Valley Ranch Trailhead.

3) Turn and Burn Maverick
Now, you should be warmed up and you're ready to begin in earnest with this ride! Take the trailhead to your left and head up Overland to the main Heil parkinglot. Then head up Wapiti Trail and turn left at the Ponderosa Loop junction (so you'll be heading clockwise on the loop, yo). Head around the Ponderosa Loop, past the lookout point (snack time) and turn left onto the Wild Turkey Trail. Go go go go! This trail is awesome! Mmmm... I love the part in the trees that gets all swoopy and full of pump turns! Sorry, got distracted here whilst writing. Left on Picture Rock! Head down towards Hall Ranch on what this author considers the best damned trail in the County!

You're going to come down to Red Gulch Rd. at the end of the Picture Rock Trail. Turn right and follow Red Gulch. which will merge with Old St. Vrain Rd (keep going right) and then dead end into S. St. Vrain Dr. Turn left here and head up Hwy 7 to the Hall Ranch Trailhead (on the right).

4) Play at Hall Ranch (part uno)
Head up Lower Bitterbrush to Upper Bitterbrush to Nelson and do a loop! Come back on down Upper Bitterbrush, but turn left at the bench and head down Antelope! Cruise down Antelope Dr. and merge right onto Apple Valley Rd. From here go about a mile and turn right onto W. Main St. (that's also Hwy 36 so keep your peepers peeled for crazy drivers in RV's coming down from Rocky Mountain National Park). Once in town, head to your favorite local eating establishment is and dig in!

5) Lunch and Beverage
Yes, this is a part of the ride. Please head on down to Oskar Blues and get some mighty fine eatin' on. Remember, you gotta get home. Throwin' the bike in the back of your friend's pickup from here is just fine if you had too many, but you can't get on the name list for 1/2 way doing this!

6) Second verse, reverse of the first!
To save myself from having my fingers fall off from typing this stuff again, basically, here is the return route

Antelope trail
Skip Upper Bitterbrush/Nelson
Left onto Lower Bitterbrush
Up Picture Rock
Left onto Wild Turkey
Left onto Ponderosa
Left onto Wapiti
Head back on dirt roads the way you came
Left Hand Trail
Sage Trail
Eagle Trail
Foothills Trail

That's right. If you do the Boulder Monster, you're name will go down here on the hall of fame! Do the ride, send in a note to BMA and we'll post your name here on the Monster Registry!

Boulder Monster Hall of Fame:
1. Raf Guevara, 6 hrs 55 min (including a root beer stop at Oskar's) - he was flying!
2. Chris Baker, (ride time 7:40 and elapsed time 9:15)
3. Mike Ranzinger, 8 hours 27 min (ride time 7:47 - 40 minutes at the Stone Cup for a BLT, yum!)
4. Dan Hickstein, 8 hrs 40 min (includes stop for pint of beer and a huge pizza)
5. Mary-Katharine Huebener, 8 hours 40 min (plus a 2-hour Oskar Blues break) ... to celebrate her birthday!

Detailed Description
The Boulder Monster is a 64 mile popular intermediate route located near Boulder County Colorado. This mountain bike only route. This route includes 18 trails. This route climbs 6,122 ft with a max elevation of 6,806 ft then descends -6,134 ft.
Local Trail Association
Local trail association
Boulder Mountainbike Alliance (bouldermountainbike.org)
Please consider joining or donating to the local riding association to support trail development & maintenance.
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34 Reviews & Comments

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  • Altitude min
    5,323 ft
  • Altitude start
    5,592 ft
  • Altitude end
    5,581 ft
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    30 miles
  • Distance down
    30 miles
  • Distance flat
    4 miles
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Upper Wapiti with the fatty - Heil Valley...
Upper Wapiti with the fatty - Heil Valley Ranch - Boulder - Colorado
1:10 | 34 | comments: 0 | favs:
Jun 30, 2023
Hall Ranch on the FATBOY - Now with extra...
Hall Ranch on the FATBOY - Now with extra GREEN Colorado
3:13 | 41 | comments: 0 | favs:
Jun 8, 2023

Recent Trail Reports Along Route

Sep 13, 2023 @ 7:59am
Sep 13, 2023
Dry, but not too dry.
Lower Bitterbrush
Sep 13, 2023 @ 7:59am
Sep 13, 2023
Dry, but not too dry.
Nelson Loop
Sep 13, 2023 @ 7:59am
Sep 13, 2023
Dry, but not too dry.
Upper Wapiti
Sep 12, 2023 @ 6:46pm
Sep 12, 2023
100% agreed with previous post. Thistle whips you if you stray out of line trying to avoid rocks. Gravel pits beat you up in some spots...
Bitterbrush Connector
Aug 31, 2023 @ 10:33am
Aug 31, 2023
Dry dry dry. !
more reports »
  • By WendyBMA BMA & contributors
  • #11830 - 2,685 views