
Big Sky Marathon is a running race on July 12, 2026 in Ennis, MT, featuring the Half Marathon and Marathon distances, with entry fees from $75 to $100.
From the Organizer
The Big Sky Marathon is the result of our success with the Madison Marathon. We held our Inaugural race in 2015 to appease marathoners from around the world who were screaming for a double (both full and half) in Montana. To non-marathoners, this is completely counter-intuitive. Afterall, why would you host a second marathon immediately after one of the most difficult marathons in America? To the likes of Marathon Maniacs and other running groups, it makes perfect sense. Why run just one marathon over a weekend when you can run two? Why not earn Four Stars as a Marathon Maniac over the course of 48 hours vs. possibly earning just one star and only if all your other stars line up?
We couldn’t answer the why not questions other than to say, ‘Yeah, why the hell not?’
We have a new route (started in 2020). It's still one hell of a downhill. Give or take it has a net drop of 3,600 feet. Turns out, it’s the Second Longest Downhill Road Marathon on Planet Earth, or at least in the top five.
The new route will once again start up on the Gravelly Range Road. The full marathon will start at approximately Mile 17 of the Madison Marathon route. Then, runners head downhill to the Madison Valley floor. Once on the valley floor, runners will no longer run along Varney Road. Instead, they will turn right at the T-junction, cross Varney Bridge over the Madison river, and run out to US Highway 287. That will be the turn-around point. Runners return to the Madison River and finish at Varney Bridge.
So for full marathoners, it will be about 22 miles out and four miles back. For Big Sky Half Marathoners, the starting line will be still up on top but not quite as high as before. It will be around five miles further down the route from the Big Sky Marathon starting line. It will then be a straight 13.1 mile shot to Varney Bridge. None to little traffic. Only a mile or so of pavement instead of more than 10 miles of pavement. And, the race ends on the tranquil waters of the Madison River, not a town park.
A good means to describe the route in terms of its challenges and level of difficulty is to break it down into three sections.
Section One – This is from the starting line to the point on the route where the significant downhill begins. The starting line is at approximately 8,500 to 8,700 feet above sea level. The full marathon start is at about Mile 17 of the Madison Marathon. The half marathon start is about 1.5 miles from the intersection of Road 292 and 290. The runners will not drop in elevation too significantly over the first five to eight miles (depending on which race you’re running). There are few or no uphills on this section of the route. It is essentially flat and on top of the Gravelly Range though everything is trending downhill. This entire section is within the Beaverhead Deerlodge National Forest. As runners get close to the border of the National Forest, there will be long, gradual downhills of two to three miles in length crossing enormous bowls and meadows, but they will not necessarily be quad burners.
Section Two – This is the quad burner section. It begins almost immediately after runners leave the National Forest. Runners will cross a cattle guard gate and then the next several miles will be a quite steep downhill. This is a series of switch backs that drop the runner from 8,500 feet to 6,000 feet in a relatively short distance. The “official end” of this section is when the road hits a t-junction after going through most of the Bar 7 ranch. The estimated distance is about seven miles.
Section Three – This section is a flat area that gradually declines in elevation as it gets close to the Madison River. The lower part of the Bar 7 Ranch is approximately 6,000 feet and Ennis and the Madison River is at about 5,000 feet. The first few miles will be on gravel road, but eventually the runners hit pavement near the Ennis Fish Hatchery turn-off. Once pavement is hit, runners are quite close to Varney Bridge and the Madison River (the finish line). When runners reach a T-junction, they turn right to Varney Bridge. The half marathon runners cross the bridge and run into the Varney Bridge Fishing Access to the finish line. The full marathoners continue on this road out to Highway 287 which is about four miles away. This section is entirely on gravel road and crosses an enormous open space area with fantastic views of both the Madison and Gravelly Range. At the highway, runners turn around and run back to Varney Bridge and the finish line.
That is how you run one of the longest downhill road marathons on Planet Earth!
Events
Weather
It's too far out for a forecast, so here's what weather on this date is normally like in the area. A race day forecast will replace this as race week approaches.
Typical High
82°
Typical Low
45°
Chance of Rain
27%
Based on US Climate Normals data from Ennis, 2 mi from the venue.
Host City
Nearest Airport
BZN
Bozeman Yellowstone International Airport · 39 mi
Time Zone
Mountain Time
From Endurance Grid
Line up lodging and travel early to lock in your race weekend.
Race Location
Approximate location — pin shows the host city, not the exact venue.
Your Next Start Line
Every finish line starts with a single decision. Claim your spot at Big Sky Marathon, put it on the calendar, and turn “someday” into a start date.
12
Days to train
Coming Up
Big Sky Community Organization Fourth of July 5K Fun Run
16 miles away
175-mile Pioneer Crossings Relay Race
13 miles away
Madison Marathon
Less than a mile away
2nd Annual Running of the Bulls Trail Race
16 miles away
From Endurance Grid
Endurance Grid is here to help you understand the sport, decide if it’s the right fit, and learn how to prepare. For course distances, logistics, and race-day specifics, always defer to the race organizer’s event page.
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Frequently Asked Questions (FAQs)
Big Sky Marathon
Jul 12, 2026