FATMAP by Strava

A River Runs Through It -> Billy Epic Loop

Combine old school freeride features with a loose, ripping descent on this high-value loop.

Mountain Biking Severe

9.8 km
424 m
425 m
1-2 hrs
Low Point
644 m
High Point
1 km
A River Runs Through It -> Billy Epic Loop Map

This fantastic route on the Whistler Westside combines old-school wooden freeride features with a ripping, loose descent into an incredible loop ride!


The ride begins on A River Runs Through It, which is home to more wooden technical trail features (TTFs) than you can shake a broken derailleur at. You'll find all manner of challenge here, ranging from extended skinnies, interwoven skinny webs with multiple options, A-Frames, teeter totters, rollers, rollercoasters, and more. Most of these features can be bypassed. Alternatively, several sections of this trail can easily be sessioned, with returning segments of singletrack to loop back up and try the TTF again. Think of this as a massive mountain bike playground, and instead of going fast through this section, focus on just playing bikes!

Interestingly, A River Runs Through It is actually located on a mostly-flat expanse of land, where the mountainside begins to level out into the valley below. This rather flat trail is quite unusual for Whistler mountain biking, but all of the features keep the engagement level high!

After finishing with the mountain bike playground, it's time to get down to work. The climb to the top follows Whip Me Snip Me to the 27 Switchbacks section of the Flank Trail. Near where you connect with 27 Switchbacks, you'll gain fantastic views looking down on the iconic Rainbow Falls—a truly beautiful and popular destination in its own right.

For many riders on non-motorized bikes, much of 27 Switchbacks will be a hike-a-bike, but strong riders can likely pedal it. Take a right where the bench cut resumes and pedal a bit further to reach the top of the descent.

Billy Epic is an old-school descent on the Westside that's somewhat isolated from the more popular trails in the network. Near the top of Billy Epic, you'll see junctions for a few trails, including some multi-use moto trails. Billy Epic itself is also open to trials motos, which leads to quite a different trail riding experience for the Westside. Look for the trail sign to pick out the correct entrance to Billy Epic.

This steep, loose descent rides the line between a single black diamond and a double black diamond. Some maps note that there are alternate double black diamond options on the way down Billy Epic, but once you drop into the gut of the descent, it's hard on a first ride to spot where the splits are and which ones are more or less difficult. It's possible that you could find yourself unknowingly dropping into the more challenging double black diamond alternate lines, so be fully prepared for all manner of gnar on this difficult downhill rip.

Unlike many other trails on the Westside, Billy Epic is quite steep and tends to get loose in dry weather. There's a substantial amount of loose, sliding scree in narrow chutes and eroded trail tread, due to the shared use status with trials motorcycles. The soil is quite unlike the typical dark black dirt found in the deep forests of BC, and once it's turned up by the motos, it makes for quite a different MTB ride style than you might be used to from the rest of Whistler. However, if you're used to riding loose scree in higher elevation zones in the Rockies, you'll make out just fine. Otherwise, the steep fall line descents with uncertain traction could be tricky.

Because of the loose soil mixed with scree, Billy Epic is a much better ride when there's some moisture in the dirt. It's also known as a good place to go for a wet-weather mountain bike ride. In part, avoiding slippery wooden bridges makes for a safer ride in wet weather.

On the lower section of the trail, you'll encounter some steep drops and rolls. One section, in particular, has several different chutes and line options to choose from, ranging from quite difficult to extremely challenging. For a few of these sets of chutes, you can pause and take a look at the lines, but others don't have much of a stop zone before you roll in. Make sure you're prepared for anything!



Widely variable, narrow trail tread with steeper grades and unavoidable obstacles of 15in/38cm tall or less. Obstacles may include unavoidable bridges 24in/61cm wide or less, large rocks, gravel, difficult root sections, and more. Ideal for advanced-level riders.

High Exposure

3 out of 4

Some trail sections have exposed ledges or steep ascents/descents where falling could cause serious injury.


2 out of 4

Away from help but easily accessed.

Best time to visit

between May and October


  • Technical
  • Singletrack
  • In the forest
  • Drops
  • Jumps
  • Roots
  • Gap Jumps
  • Tabletops
  • Rock Rolls
  • Rock Slabs
  • Rock Gardens
  • Wooden Feature

Similar routes nearby

Guidebooks in this area