National Forest Scenic Byways
Sky Island Parkway, Arizona
The National Forest Service has designated many roads across America as National Forest Scenic Byways. These roads are not always paved and often enough require high clearance and 4WD in the hands of an experienced driver.
The list below is as complete as I can make it but there's no guarantee that I got all the roads... there's a lot of them. And many of these roads are also part of a greater system of scenic byways, although many are designated byways only for those stretches that cross National Forest. There are some states where the only designated scenic byways are National Forest Scenic Byways...
US Forest Service Scenic Byways
Along the Cache La Poudre-North Park Scenic Byway, Colorado
Bottom photo courtesy of TheArmchairExplorer, CCA-by-SA 4.0 License