No Map, Severely Ill on 760-Mile FKT: Colorado's Wild Trek

Hunter Leininger's Colorado Traverse FKT: A Test of Resilience and Adaptability

Hunter Leininger, a 26-year-old adventure racer and endurance athlete, has built a reputation for tackling some of the most grueling outdoor challenges. He holds FKT records for the Florida Trail, the North-to-South Iceland Traverse, and the U.K.’s Skye Trail, among others. In 2024, he completed a 400km self-supported race across China’s Gobi Desert, finishing 9th. However, his recent attempt to set an FKT traversing the state of Colorado may have been the most challenging yet.

The Colorado Traverse FKT began on June 29, 2025, with Leininger aiming to cover 760 miles through the Rocky Mountains, climbing approximately 350,000 vertical feet. He finished on July 16, completing the route in 17 days, 23 hours, and 40 minutes. This achievement was particularly significant because no one had ever successfully completed an FKT on this route before.

Leininger had been eyeing this goal for 17 years, and when he had no races scheduled this summer, he decided to take on the challenge. “I just wanted to do something that I really wanted to do,” he said. The lack of prior attempts only added to his motivation.

A Challenging Start

Leininger’s journey didn’t go as planned from the beginning. On the first day, he felt extremely unwell, experiencing a high heart rate, coughing, and difficulty breathing. By the third day, his phone broke, leaving him without navigation and communication tools. He used a flip phone, which had a non-functional screen but still allowed him to answer calls. His mother helped navigate from 2,000 miles away, a surreal experience for both.

He also faced other obstacles, including getting lost multiple times due to the lack of clear trail markers. Without a map, he struggled to locate water resupplies, leading to a dangerous situation where he ran out of water on a 25-mile stretch. This forced him to borrow a hiker’s phone and call his father for help, ultimately shifting his FKT from "Unsupported" to "Supported."

Adjusting Strategy

After receiving a new phone, Leininger adjusted his strategy. He traveled with support, sleeping in an ambulance converted into an RV. This change allowed him to complete about 55 miles per day, significantly faster than he could have managed alone. Despite the shift, he continued to face health issues, including a respiratory infection that left him feeling sick for nearly 18 days.

Physically, his legs remained strong throughout the journey, but his lungs were a constant struggle. He never experienced physical fatigue or soreness, but the illness made the entire trip extremely difficult. “I never bonked, and I never had any physical problems,” he noted. “My legs were about 100% until the very end.”

Gear Issues and the Shift to Support

Leininger also faced serious gear-related challenges. His backpack’s shoulder strap ripped off within the first three days, and his sleeping pad popped, forcing him to sleep on the cold ground. His sleeping bag got soaked and wouldn’t dry, compounding his difficulties.

However, once he transitioned to a supported FKT, many of these issues were resolved. He could travel lighter and focus on essential gear. Key items that made a difference included:

• VKTRY Carbon Insoles: “These were my secret weapon on this run. I wore them in my shoes every day.”
• VKTRY Inside Edge Compression Socks: “They automatically flex your foot forward … it almost feels spring-loaded.”
• Enlightened Equipment Copperfield Wind Shirt
• GORE Wear Concurve GORE-TEX Rain Jacket
• HOKA Stinson 7: Two pairs

Reflections and Future Plans

Despite the challenges, Leininger expressed gratitude for the experience. “I’m grateful for being sick and suffering, but also feeling really fresh and fast and being able to run,” he said. However, he doesn’t plan to attempt the Colorado Traverse again. “I don’t think I have any desire to come back and do it again,” he admitted. He now sees the value in supported FKT attempts, especially for longer routes.

Leininger’s journey highlights the extreme mental and physical demands of self-supported long-distance running. While he succeeded in completing the route, the experience left him with a deeper appreciation for the challenges involved. For now, he plans to continue exploring ultra-running, but with a more balanced approach.