Headwaters of the Frio Trail Marathon, Half, 12K, 5K

About the Course​ ​

7,050 acre ​Big Springs Ranch is 11.5 miles long and up to 2 miles wide. Most of the land is virtually untouched by humans. The course winds through a wide variety of spectacular Hill Country terrain. It's truly one of the most ranches in all of Texas. 

First and foremost you should know that this is a trail, rather than a paved road course. Don't expect miles of smooth pavement. Less than a mile of the surface is paved road with the majority of the course taking place on dirt and rock ranch roads. These roads are in pretty good shape, but there will always be some rough patches. There are also 3 miles of hilly, single track trail on the marathon and half marathon course.

You will climb to the top of ridges and descend to river valleys, traverse canyons, forests and meadows, ford streams and pass Big Springs at the headwaters of the Frio River. Water and aid stations will be located every 2-3 miles along the course along with a bathroom on the half marathon and marathon courses.

There is an incredible variety of animal life along the trail including Whitetail deer, Red deer, Axis, Aoudad, Wild Pigs, Coyotes, Horses, Longhorn Cattle, Wild Turkey, Jackrabbits, Lizards, Turtles, Red Tailed Hawks, Great Blue Herons, Hummingbirds and other birds species too numerous to list. 

The route is a treat for the senses as you run or walk under the shade of oak trees, smell the cedars and Texas mountain laurel and traverse through native grasses punctuated with the vivid hues of wildflowers. 

The few traces of man’s presence are relics of a bygone age: an 1896 homesteader’s cabin and grave site, a model T car from Mexico abandoned along the road, a campsite where a Chicago gangster hid out in the 1930’s, and there’s even rumor of buried treasure near Horse Collar Bluff.

Stretching back much further in time, the most incredible aspect of the route is you will literally run/walk in the footprints of dinosaurs! There are two areas of dry riverbed with dozens of well-preserved tracks from a variety of dinosaur species. This is truly one of the most unique and interesting marathon courses in the world!

There are only 250 spots available for this event, so sign up soon!


Course Map




5K Course Elevation Profile


12K Marathon Course Profile




Half Marathon Course Profile