The Grand Mesa National Scenic Byway is a National Scenic Byway, National Forest Scenic Byway, and Colorado Scenic and Historic Byway located in Delta and Mesa counties, Colorado, USA. The byway traverses Grand Mesa, the most extensive flat-topped mountain on Earth, and reaches an elevation of . The byway comprises Colorado State Highway 65 from Cedaredge to Interstate 70 Exit 49 and Forest Service Road 100 to the Land's End Observatory.