Once you get to Cottonmill, you can ride the variety of small mountain bike trails they have through the park (typically following the disc golf route), but you can also head towards the back of the park by following the road. You'll see a big sign and wood chips at the beginning of the trail (there's at least 2 spots to enter). These trails will take you up and behind Cottonmill, for a great view and some steep hills to challenge yourself on. There's some great downhill spots, and you can even break free from the trail at the turnaround point and ride onto some smoothly packed dirt roads.
Cottonmill Park is on the west boarders of Kearney, and is connected to town by a bike trail. There are some mountain bike paths within the park, in between the trees, and some much better open trails behind the park and accessed through riding to the back of the park where the road ends.
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