50 Mile and 30 Mile Courses

2021 Course Information


First, this race would not be possible without the cooperation and generosity of several land owners and managers in the Big Sky area.  Our courses travel in and out of private and public lands.  Putting the routes together, while being mindful of hazards, roads, horse traffic, easements and just good ole’ fashioned manners was not easy.   There were numerous conversations, edits, phone calls, meetings, more edits, and then more favors being asked.

UPDATED JULY 8, 2021:  The course maps are now final.   Both distances will utilize the same course maps from 2019.   While we wanted to extend the “50 Mile Course” to a 100k, we are not able to tie into the extended single-track yet, due to construction and development in the area.  We suspect most of you will not mind 🙂

50 Mile Course

48~ Miles
Elevation Gain: 9,000+ ft
Single-track: 39 miles
Double-track or Dirt Road: 5 miles
Pavement: 4 miles

2021 BIG SKY BIGGIE – 50 MILE COURSE on Trailforks.com

30 Mile Course

29~ Miles
Elevation Gain: 4,849 ft
Single-track: 21 miles
Double-track or Dirt Road: 5 miles
Pavement: 4 miles

Time Cut-Offs

Look, nobody wants to pull you from the race.  Our whole mission is to provide you with an amazing day on the bike and watch you suceed.  However, we have 13 different land-use permits and agreement with land-owners for this event, which require us to vacate their land so that their normal daily operations may continue (guided horseback tours at Lone Mountain Ranch, downhill bike traffic at Big Sky Resort are a couple of examples).    We rely on volunteers who donate their entire day to the event.   But we need to have their safety in mind and will not ask them to stay out on the course for longer than is reasonable.    We ask that you have these priorities in mind (land use agreements and safety) if we ask you to scratch from the event. 

Time cut-off for the 50 Mile Course is at Aid Station #3 at 1:00pm
If 50 Mile racers have not arrived to Aid Station #3 (Critical Junction) by 1:00pm, then they will be routed to the finish, using the 30 mile course.  They will be a DNF for their event.

There are no time cut-offs for the 30 Mile Course. 
However, if our safety team and sweepers determine that it’s in the best interest of the race for you to scratch at a certain point, we will ask you to do so.  




Starting in Town Center, participants will ride pavement for .3 miles, winding through a small subdivision to the Lone Mountain Ranch property.   You will then gradually start climbing on a double-track (dirt road), which will hopefully spread out the pack, for roughly a mile.   The course narrows to a straight, single-track, steadily climbing for another mile or so.   You’ll cross a bridge (North Fork) and ride a double-track to the North Fork trailhead parking lot.  <—  This section, from the starting line to North Fork Traihead is NOT open to the public for pre-riding.

From the North Fork trailhead parking lot, you will climb the Ridge Road (dirt road) for two miles, and then get on the Ridge Trail (single-track, FS 403) and climb all the way to where it ends at the Beehive Basin subdivision.   This is a 4 mile climb at a 6% grade, climbing approximately 1,400 ft, also known as “NF Trailhead to Beehive Pavement” on Strava.  <— This entire section is open to pre-riding.

You’ll take a left onto a dirt road, which turns into pavement and begin descending through a quiet subdivision.   This is a steep descent, with a couple of hairpin turns.   You’ll have speed, so look ahead and be careful on the sharp corners.   Roadies will love this section.  (The rest of you will question why we have you descending on pavement.   Please trust that we lobbied hard to use an existing FS trail, but we lost the battle again.  We’ll keep trying!)  <—  This section is NOT open to the public for pre-riding.

You’ll arrive at the Upper Beehive Basin Trailhead, where you will turn left onto single-track that parallels the Beehive Basin Road, all the way to the top of the Cascade Lift.    You’ll then descend steeply down underneath the Cascade Lift, and go through the skier tunnel (under Highway 64).   This little section was cut-in by volunteers.  It’s rugged – be careful!

BIG SKY RESORT / Moonlight Trails

From the skier tunnel (under Highway 64), you’ll pop out into the Big Sky Resort area, and be routed through some dirt roads and single-track to Aid Station #1 at the bottom of the Swiftcurrent lift (the Resort Base).

There will be a junction here where our 100K/60 Mile racers will do a super fun loop around Madison Base area, for roughly 12 miles.  This is the new section for the longer course, and we’re still creating this route.

BIG SKY RESORT / Andesite Mountain

From the Big Sky Resort Base area, you’ll start climbing up Andesite Mountain.

100K/60 Mile racers will turn left into the Coolridge track for a few extra miles, before rejoining this trail on the way to Mountain to Meadow.

30 Mile racers will continue to climb approximately half-way up Andesite Mountain until you get to the start of the famous Mountain to Meadow trail descent.

This is a classic downhill trail which starts at Big Sky Resort and descends approximately 2,200 feet to the Meadow area.  There could be non-race traffic on this section.  You are expected to use proper trail etiquette.   If you want to pass, let the rider in front of you know, but wait for them to acknowledge and move out of your way.  <— This entire section is open to pre-riding.


At the bottom of the Mountain to Meadow Trails (M2M) you’ll get to Aid Station #2.   Refill and refuel before starting an easy pavement spin up through the Spanish Peaks subdivision.   After the climb, you’ll start another long 2.75 mile -4% descent on a flow trail, locally known as Fishcamp.  This section is on private land and NOT open to the general public.   You’re going to be grinning from ear to ear – this section is awesome.   But be mindful that the trail crosses a paved main road in three places.    We will have crossing guards, but please ride safely when crossing, as you will be approaching with significant speed.   At the bottom of Fishcamp, riders will cross a bridge (Ousel Falls West Fork) and ride a short double-track section over to a paved road.  <—  This section is NOT open to the public for pre-riding.


This is where the 50 Mile course participants turn right, crossing the paved road to do the Yellow Mules Loop.

The 30 Mile course participants will turn left, as they head towards Ralph’s Pass.   We will have signs, crossing guards and course marshals at this critical junction to make sure nobody takes a wrong turn.    If there is a thunderstorm on Buck Ridge, at the top of the Yellow Mules Loop, with electricity, this is also the place that we will make a judgement call and direct all racers to the finish route.

Time cut-off for the 50 mile racers at Aid Station #3:  12:00pm
If 50 mile racers have not arrived to Aid Station #3 (Critical Junction) by 12:00pm, then they will be routed to the finish, using the 30 mile course.

(30 Mile course participants – jump down to the next section for the finish route.)

YELLOW MULES LOOP  – for the 100K/62 Mile Course only

From the paved road, you’ll ride 1.5 miles to the Yellow Mules junction.  This 1.5 mile section will have two-way traffic.  This is the only place on the course with two-way traffic, and with how spread out the 100K/62 Mile riders will be at this point in the day, it shouldn’t be too concerning.

Once you reach the junction, you are going to turn right onto Second Yellow Mule. There are signs here, and it will be well-marked.    Now, find your happy place and start climbing.  The entire Second Yellow Mule climb is approximately 10 miles, 2,800 ft gain at about 4% average grade.    The first 4 mile of this climb are not bad.  You’ll cross through some streams, and it’s rocky in some sections, but for the most part, it’s a smooth, continual climb.   Then you’ll get to the bridge.    Make sure you are eating and drinking.  And prepare yourself for the final steep, grunt of a climb.   The view at the top of Buck Ridge is worth it.

Once you’ve reached the top of the climb, you’ll be riding on top of Buck Ridge heading East towards First Yellow Mule.  We will have a Safety + Aid station setup here.   There will be some search and rescue staff, as well.   The weather can be much different up on Buck Ridge, compared to the rest of the course, so it’s wise to have some sort of light shell you can throw on if there is a thunderstorm rolling in.

Descending First Yellow Mule might be the highlight of the course.  It’s rugged.   It’s old-school.  And the view is incredibly distracting.  Depending on the season, there might be a trench, so watch for pedal strikes.  If you just endured the climb up second Yellow Mule on a heavy, long-travel bike – this is your opportunity to open ‘er up and let it rip!   You’ll be descending for five (5) glorious miles, and once you reach the Yellow Mules junction, you’ll turn right, and go back out the 1.5 mile two-way traffic section.    Please YIELD TO THE UPHILL RIDER.   Bombing down this 1.5 mile section without regard for uphill traffic makes you look like a jerk, and it will not win you the race.

Once you get to the paved road, LOOK FOR TRAFFIC, and then go straight across the road to the singletrack on the other side.  Again, we will have crossing guards and signs here.   <— This entire section is open to pre-riding.

FINISH ROUTE  – for the 100K/62 Mile and 30 Mile Course

It will feel like you’re almost done.  And you are close.  But we hope you saved something, because this last section is a little bit of an ass-kicker.   You’ll ride Ralph’s Pass, a newer, smooth-as-butter trail to connect you from First Yellow Mule to Uplands.   Ralph’s Pass is funky – steep in sections – and the switchbacks may have you cursing, or walking.
Oh, hey, check out this cool video from BSCO about the construction of Ralph’s Pass »

Be mindful of other riders and foot traffic, especially now that you’re getting closer to Town Center.    There are several places this trail crosses another trail, and some roads, but we will have it well-marked.

Ralph’s Pass ends at Uplands, where you’ll turn left.   And now, you are definitely close to the finish.   Enjoy the last bit of singletrack down to the Uplands & Hummocks Trailhead.  Then turn right onto Aspen Leaf Drive and follow the paved road all the way to the Finish.   <— This entire section is open to pre-riding.

Presented By

With tremendous support from these Primary Sponsors in 2021

WONDERBUILD.com - Official Sponsor of the Big Sky Biggie

And our 2021 Supporting Sponsors

Spanish Peaks Community Foundation - proud sponsor of Big Sky Bigge mountain bike race