Routes

Planner

Features

Updates

App

Login or Signup

Get the App

Login or Signup

Routes
Mountain biking trails
United States
California
Los Angeles County
Monrovia

Lower Clamshell Truck Trail

Moderate

2.7

(21)

67

riders

Lower Clamshell Truck Trail

01:11

10.2km

340m

Mountain biking

The Lower Clamshell Truck Trail offers a diverse mountain biking adventure through the Monrovia Hillside Wilderness Preserve, blending wide fire roads with engaging singletrack. You'll navigate through canyons and encounter numerous steep, tight switchbacks that demand good control, especially on descents. The highlight is undoubtedly the Sunset Overlook, providing expansive views that can stretch all the way to downtown Los Angeles on a clear day, making this a rewarding ride for those who enjoy varied terrain.

To make the most of your ride, plan to access the trail near Ridgeside Drive, keeping in mind that parking might require a short walk to the trailhead. It's strongly advised to ride the 6.4 miles (10.2 km) route counterclockwise, starting near Canyon Park, to avoid inadvertently straying onto private land. This moderate trail, with its 1114 feet (340 metres) of elevation gain, typically takes about 1 hour and 10 minutes to complete, so an early start is often best.

This trail stands out in the region for its unique mix of terrain, offering both speed on fire roads and technical challenges on singletrack. It's a popular choice for mountain bikers in the Los Angeles County area, providing a solid workout and impressive vistas without being an all-day commitment. The dog-friendly nature of the trail also makes it a great option if you want to bring your leashed canine companion along for the ride.

Last updated: June 9, 2026

Waypoints

A

Start point

Get Directions

1

2.16 km

Monrovia Hillside Wilderness Preserve

Highlight • Trail

Mostly smooth fire road through Monrovia Hillside Wilderness, but with some steep and technical sections that might challenge beginners. Ride counterclockwise from Canyon Park and follow the signs—many side trails cross private land. The descent includes tight switchbacks and a short singletrack section. You can stick to the main road or take the “advanced” trail, Cactus Road, for more climbs, exposure, and a fun technical finish.

Tip by

B

10.2 km

End point

Loading

Way Types & Surfaces

Way Types

9.03 km

1.21 km

Surfaces

10.00 km

243 m

Sign up to see more specific route details

Sign up for free

Elevation

Elevation

Nothing selected – click and drag below to see the stats for a specific part of the route.

Highest point (460 m)

Lowest point (250 m)

Sign up to see more specific route details

Sign up for free

Weather

Powered by Foreca

Monday 6 July

29°C

16°C

0 %

Additional weather tips

Max wind speed: 7.0 km/h

to get more detailed weather forecasts along your route

Comments

guide_signup

Want to know more?

Sign up for a free komoot account to join the conversation.

Sign up for free

This route was planned by komoot.

Save

Edit route

Download GPX

Move start point

Print

Share

Embed on a website

Report an Issue

Report restricted access

Frequently Asked Questions

Where can I park to access the Lower Clamshell Truck Trail?

Access to the trail is typically from areas around Ridgeside Drive. Be aware that parking might require a short walk to reach the actual trailhead.

Is this trail suitable for beginner mountain bikers?

The Lower Clamshell Truck Trail is generally rated as 'moderate' or 'blue' difficulty. While it features wide fire road sections that are less technical, there's also a significant singletrack section with steep, tight switchbacks that can be challenging. Beginners should be prepared for varied terrain and potentially dismount on the more technical parts.

What kind of terrain can I expect on this mountain bike trail?

You'll encounter a mix of terrain. Much of the route is a wide fire road, but it transitions into a challenging singletrack section with numerous steep and tight switchbacks, especially towards the summit. Expect loose dirt and rocks, particularly on steeper sections. Some areas, like the switchbacks below Sunset Bench, have seen recent grooming, but ruts and washed-out tread can still be present.

What scenic views or points of interest will I encounter?

Riding this route offers beautiful views into the San Gabriel Valley and of the surrounding mountain ranges. Keep an eye out for the 'Sunset Bench,' which is a notable viewpoint along the way. The trail is located within the Monrovia Hillside Wilderness Preserve, providing a pleasant natural backdrop.

Is the Lower Clamshell Truck Trail dog-friendly?

Yes, dogs are permitted on the trail. Please ensure they are kept on a leash at all times to protect wildlife and for the safety of other trail users.

Are there any permits or fees required to ride in the Monrovia Hillside Wilderness Preserve?

Generally, there are no specific permits or entrance fees required to access the trails within the Monrovia Hillside Wilderness Preserve, including this route. However, always check local regulations before your visit, as conditions can change.

What is the best time of year to mountain bike this route?

Spring and fall typically offer the most pleasant riding conditions with milder temperatures. Summer can be very hot, so early morning rides are recommended if you go during this season. Winter can be nice, but be mindful of potential rain, which can make some sections muddy or rutted.

Does this route connect to other trails?

Yes, the Lower Clamshell Truck Trail is part of a larger network. It connects to other paths like the Monrovia Canyon Truck Trail and the Bill Cull Trail, offering options for extended rides. The route itself also passes through sections of the Cloverleaf Drive and Cactus Cooler trails.

Is this a loop trail, or out-and-back?

The Lower Clamshell Truck Trail itself is not a complete loop. However, it can be combined with other trails in the network to create various loop options, depending on your desired distance and difficulty.

How are the trail conditions typically?

Conditions can vary. While some sections, particularly the switchbacks, have been noted for recent grooming, you should still expect areas with loose dirt, rocks, and potential ruts or washed-out tread, especially after rain. It's always a good idea to check recent trail reports before heading out.

Is this a popular trail, and can it get crowded?

Yes, the Lower Clamshell Truck Trail is quite popular, indicating its appeal to many mountain bikers and hikers. Due to its popularity, you might encounter other users, especially on weekends and during peak hours. Arriving earlier in the day can help avoid larger crowds.

Nearby routes

Hard

4.5

17

Glendora Mountain Road and Lower Monroe Truck Trail

03:36h

38.9km

1,190m

Explore
RoutesRoute plannerFeaturesHikesMTB TrailsRoad cycling routesBikepackingSitemap
Download the app
Follow Us on Socials

© komoot GmbH

Privacy Policy