MTB Project Logo

Lower Monroe Truck Trail



16.1 mile 25.9 kilometer out and back
65% Singletrack


Ascent: 2,319' 707 m
Descent: -2,319' -707 m
High: 3,435' 1,047 m
Low: 1,201' 366 m


Avg Grade: 5% (3°)
Max Grade: 14% (8°)


Driving directions Take a virtual tour
Zoom in to see details
Map Key

Trail shared by Aviv Bar

A great doubletrack to the top of Glendora Mountain Road and a screaming downhill.

Aviv Bar

Electric Mountain Bikes Unknown

Features -none-


The Lower Monroe Truck Trail combines a flat doubletrack rock garden with a steady but gradual eight-mile twisty climb to the top of Glendora Mountain Road. The reward comes in the form of a scenic eight-mile descent back to the start point.

Need to Know

A large parking area is available along Glendora Mountain Road approximately 1/2 mile south of the trailhead and in smaller patches leading into the trailhead.


The ride begins through a fairly flat rock garden creek, a bumpy and twisty 1.7-mile section with intermittent tree cover, but nothing extremely technical. The trail is mostly doubletrack, but narrows to singletrack in various spots along the rock garden.

At the end of the rock garden, the doubletrack takes a sharp right turn to begin a 6.2-mile climb. The climb is not extremely difficult, but it is steady with a very small number of flat areas and short descents along the way. A majority of the ride does not contain any tree cover.

At 3.3 miles, there is a plateau with amazing views of the San Gabriel Valley and south towards Orange County. This is a popular rest point before the climb gets a bit steeper.

From the rest point, the trail continues to climb as it winds along various sides of the mountains, providing great scenery. The trail ends at a turn-around point with a gate that leads to a dirt parking lot, adjacent to Glendora Mountain Road. If you want to skip the climb workout, you can shuttle to this parking lot and downhill the trail all day long.

Making a 180° turn at the gate will send you right back down the way you came up, but at a MUCH faster pace. The ride down Lower Monroe Truck Trail can be compared to a downhill park without the crazy jumps and super sharp turns. It is a fast-paced. twisty ride, negotiating a trail that is rocky and rutted in many places with trail-hugging vegetation.

The downhill seems to last forever and is guaranteed to put a constant smile on your face. On the lower area of the descent, you may encounter a few pedestrians, so a cowbell will serve your downhill well.

Also full-finger length gloves are highly recommended during dry summer months, to protect yourself against those handlebar-level thorny plants. Since you'll be exposed to the sun for the majority of the trail, a good supply of water is also recommended.

Biked this trail?

We need help with the following missing trail information:

Family Friendly, ADA Accessible, Dogs Allowed, Features, Electic Mountain Bikes Allowed, History & Background


Rate This Ride

Rate Quality

   Clear Rating

Rate Difficulty

Share This Ride

Check In


Feb 21, 2020
Mac Martinez
Feb 13, 2020
Mac Martinez
First ride on the trail
Jan 26, 2020
Andy Somerville
Trail is in excellent shape. Minimal ruts, easy stream crossings, hero dirt! 16mi — 2h 30m
Jan 11, 2020
Martin Pagh Ludvigsen
15.9mi — 1h 52m
Aug 7, 2019
Shon G
Jun 16, 2019
Joseph Eby
Mystic to Monrovia Trail to GMR/GRR to Barrett Stoddard 40mi — 5h 00m
May 11, 2019
Martin Pagh Ludvigsen
damn, that climb was hard 16.1mi — 18h 00m
Apr 16, 2019
Riley Cortez

Trail Ratings

  4.2 from 64 votes


  4.2 from 64 votes
5 Star
4 Star
3 Star
2 Star
1 Star
Ride Rankings


in California


203 Views Last Month
23,249 Since May 29, 2014



Feb 1, 2016 near San Dimas, CA
Climbing up, about a mile north of Mystic Cyn.
Nov 26, 2015 near Glendora, CA
GMR viewed from Mystic Canyon
Oct 11, 2015 near Glendora, CA
Mystic Canyon
Oct 11, 2015 near Glendora, CA
Lower Monroe Trail Guide
Sep 23, 2018 near Glendora, CA
GMR, Lower Monroe Truck Trail, Glendora, CA
Jan 11, 2016 near Glendora, CA

MTB Project is part of the REI Co-op family,
where a life outdoors is a life well lived.

Shop REI Mountain Bike

MTB Project is supported by

Support Your Local IMBA Chapter