Have you heard of the “Million Dollar Highway”? It is US 550 between Silverton, Durango and Ouray (Colorado). This stretch of of road is not very long but it will take you a while to traverse it as it winds through the mountains with stretches having speed limits of 25 MPH. There are steep drop offs and curves. The drop offs are in the hundreds to thousands of feet, but there is no guardrail. You have to be very careful driving this road.
I strung together several clips when driving north on the way into Ouray.