We are excited to have once again secured the remote Weldon Spring Conservation Area and its excessive trail system for our 2025 MammothMarch Missouri edition. Hike 20 miles along a great mixture of diverse trails, such as Katy Trail and Lewis & Clark Trail featuring superb overlooks of the Missouri River.

Our single-circuit hiking loop starts and finishes at the beautiful Defiance Ridge Vineyards, located just half an hour west of St. Louis.

Master the challenge and spend a beautiful day hiking 20 miles at a stretch. Getting your finisher medal, you will be exhausted but proud and happy… as well as part of our amazing community of nature-lovers, hikers and MammothMarch addicts!

Signing up for the first time? Take a look at past events and what our participants say: https://www.mammothmarch.com/reviews