When you drive a car over a covered bridge, it's easy to feel like you should be in a horse-drawn carriage instead. They call to mind quaint New England towns, vibrant fall leaves, and a simpler era.

HARDENBURGH, N.Y. — Marks Buerge grew up walking alongside the trusses of the Millbrook Bridge, built across a stream in the town by his grandfather in 1902. The 66-foot-long bridge, formerly known as ...