Tulsa got beat by Flagstaff and it's population is about 60k.
Flagstaff, Az.
The outdoors-obsessed discovered Flagstaff decades ago, drawn by abundant park access both inside and outside city limits. Not surprisingly, the Flagstaff Urban Trails System, or FUTS (pronounced "foots"), is one of the best small city networks on the continent. The city boasts 50 miles of trails, with plans to add another 80 miles. Only fifty-percent of the FUTS is paved, no doubt so mountain bikers and trail runners can keep on their treads without leaving the city limits. Flagstaffers easily access the Arizona Trail, the 800-mile recreation trail that runs from the Mexican border to Utah, including 17.3 moderate miles within the city limits spanning from Fisher Point to Schultz Pass.