Get ready for some fun in the sun and a great mid-season test of your training as we bring our 11th Annual Dog Days 5K, 10K & Half Marathon! Centrally located between Denver & Boulder along with its Endless Series sidekick in December Fa La La, the beauty of our breathtaking Flatirons as a backdrop will inspire you every step of the way along Big Dry Creek Trail, well known as a Colorado favorite!