America's covered bridges were built with a handful of distinct wooden truss designs, the engineering skeleton hidden inside each bridge. Below, 446 bridges in our directory are organized by their primary truss type. (Bridges whose truss type isn't documented aren't listed here; find them on the full A-Z index.)

Burr Arch Truss (181 bridges)

The most common design in the directory: an arch layered over multiple kingpost trusses, patented by Theodore Burr.

Town Lattice Truss (53 bridges)

A web of criss-crossed planks pinned with wooden pegs, patented by Ithiel Town.

Paddleford Truss (14 bridges)

A New England specialty and the signature form of northern New Hampshire, an unpatented interlocking truss developed by Peter Paddleford of Littleton.

Howe Truss (83 bridges)

An iron-and-wood truss with vertical iron rods, the workhorse of Oregon and the West.

Multiple King Post Truss (32 bridges)

A series of triangles: simple, strong, and common in Ohio.

Queen Post Truss (34 bridges)

A king post stretched with a horizontal top, spanning slightly longer gaps.

King Post Truss (17 bridges)

The simplest truss, a single central triangle.

Smith Truss (9 bridges)

A patented diagonal truss by the Smith Bridge Company of Ohio.

Childs Truss (6 bridges)

A rare Ohio design with iron diagonals, patented by Horace Childs.

Long Truss (6 bridges)

An all-timber panel truss patented by Stephen H. Long.

Pratt Truss (7 bridges)

A truss with diagonals in tension, more common in metal bridges than in covered wood.

Stringer (2 bridges)

Simple beam construction, typically on shorter or rebuilt spans.

Brown Truss (1 bridges)

A lightweight diagonal truss patented by Josiah Brown.

Other / Unusual Designs (1 bridges)

Unusual or one-off engineering, such as inverted Haupt designs.