9th Annual Madison Duathlon

Ennis, MT 59729, USA



Thanks for your interest in the Greater Yellowstone Adventure Series (GYAS) races.  We have not cancelled the GYAS events for 2020.  However, we have temporarily closed our registration for all the races until the situation becomes more clear.  Montana is under Phase One of its opening which limits group sizes to no more than 10 people.  If the Governor decides to go to Phase Two, groups of up to 50 people will be allowed.  At that time, we will try to obtain race permits to allow some or all of our races to be held in a limited format as originally scheduled from July 16 to July 26.  There is no guarantee that we can obtain permits under Phase Two, but it’s our intent to try and do so.


Please sign up for our newsletter to keep in the loop on this situation.  Go to our race website – www.themadisonmarathon.com – and click on the newsletter ‘Stay in the Loop’ link to get on the mailing list.  Thank you.


Stay Happy, Healthy, and Always Keep Running Forward.


Sam Korsmoe

Race Director

Greater Yellowstone Adventure Series

 Olympic Distance Duathlon

Run: 3 kilometers 

Bike: 40 kilometers

Run: 10 kilometers


Second Leg of the Madison Trifecta​ (a.k.a. Trifecta World Cup - Yellowstone)

The original Madison Duathlon (bike/run) started out as a natural expansion of a good idea (i.e. the Madison Marathon), but it quickly became a good idea on its own.  It was an A to B that started in Ennis right near the banks of the Madison River and then went up and over the mountains to Virginia City.  It was a great route and many duathletes who have competed in the Madison Marathon say they had more fun on the duathlon.​

Not to screw with success, but we have a new route and new format starting in 2020.  First, it will be an Olympic Duathlon.  This means a run-bike-run race at distances of 3K-40K-10K. 

The start and finish will be at Lion's Club Park in Ennis.  The first run will essentially be a sprint of sorts.  The route comes out of Lion's Park, crosses the Madison River, and then comes back.  The cycling route is entirely on Montana Highway 287.  Cyclists head towards Virginia City.  They go up a mammoth hill, down the other side for a bit, and then turn around. After a short uphill, they have an incredible downhill in full view of the Madison Range.  They re-enter Lion's Park, jump off their bikes, change their shoes if necessary, and do a 10K loop run with the finish line also in Lion's Club Park.

The cycling leg, unlike before, is entirely a road race.  This means road bikes and, for some of you, serious speed.  The hills though are huge so it won't be easy.

The new format and date (Friday morning) is to accommodate the plans for the Trifecta World Cup.  The duathlon is the second leg of the Madison Trifecta.  The first leg is Thursday evening (Madison Triathlon), the second leg is this duathlon, and the third and final leg is the very next morning with the Madison Marathon. 

You get all three races in, and you're a TBA- Total Bad Ass!

If you get just this duathlon in, you're a bit of a bad ass as well.  At the very least, you get to participate in Montana's only Olympic duathlon.  That alone is pretty bad ass!

See you in July!