The aspens are turning, and the air has taken on that definitively crisp feel of autumn in Colorado. Cooler temperatures and crunchy fallen leaves beg to be enjoyed and stepped upon, respectively.

There’s no better way to oblige them than by taking a nice, long trail run through the woods. And there’s no better place to trail run than in the mountains. The challenging 4.5-mile Sombrero Trail Run this weekend in Estes Park is a fitting way to celebrate the season.

The course—which is apparently steep, rocky, and far from easy—promises to get your legs and lungs working overtime with around 900 feet of total elevation gain. In the gym, this kind of workout would be nothing but painful. But with breathtaking views of mountain vistas, golden swatches of aspen—the leaves turn sooner up there, remember—and the Continental Divide to pacify all that huffing and puffing, it will surely be worth it.

But the run is just the start of the fun. Participants are invited to stick around for a free, all-you-can-eat pancake breakfast with sausage, scrambled eggs, orange juice, and "cowboy"—code for strong—coffee. This is the time to congratulate fellow runners, make new friends, and take a minute or two to relax on the Sombrero Ranch and appreciate the beauty of fall at a mile-plus high. (Spectators can eat for $5.)

Register before Thursday, September 16 at the website linked above to receive the early-bird price of $30. Registration is also available on race day for $35.

Bonus: Well-behaved, leashed dogs are welcome on this BolderBOULDER qualifier run.