The Longley Covered Bridge is located in a rural area northwest of the village center of Montgomery, on Longley Bridge Road just west of its junction with Vermont Route 118.

It crosses the Trout River in an east–west orientation, resting on abutments of stone and concrete.

The bridge consists of flanking Town lattice trusses 84.5 feet (25.8 m) long.

The exterior is finished in vertical board siding, which extends around to the interior of the portals.

The bridge deck consists of wooden planking, and reinforcing stringers have been added to its underside.