The most incredible way to see the Arkansas River Valley, from clifftop and treetop, is on a 44-acre, private zipline course at the Granite Outpost north of Buena Vista, Colorado.?Seven cable lines?travel?over 3,500 total feet. Leap into the air from platforms built into natural features like cliffs and treetops. Finish off the 3-hour adventure with a 900-foot dual-race line that leaves guests breathless, yet smiling, from ear to ear.