East portal of summit tunnel. Western summit. Length 1,660 feet

Donner Lake, Tunnels No. 7 and 8 from Summit Tunnel, eastern summit in distance

Section of Penn. R. R. tunnel under the Hudson River at N. Y. City, exhibited at World's Fair, St. Louis, Mo., 1904. Diameter 21 feet

Bend of the Weber, Upper Weber Kanyon, near Tunnel No. Three, looking east.

Bend of the Weber, Upper Weber Kanyon, near Tunnel no. Three looking, east.

Tunnel No. 3, Weber Canon. U.P.R.R.

Tunnel No. 3, Weber [River].

Tunnel No. 3 and Weber River.

West End Tunnel No. 3.

Tunnel near Devil's Gate.

Railroad tunnel.

Black Rock Tunnel, near Phoenixville.

Tunnel near Greensburg.

Columbia Tunnel.

Allegheny Tunnel.

Allegheny Tunnel.

Blairsville Tunnel.

Carr’s Tunnel.

The Allegheny Tunnel.

The Allegheny Tunnel.

The Allegheny Tunnel.

Allegheny Tunnel.

Allegheny Tunnel.

Spruce Creek tunnel.

Spruce Creek tunnel.

Columbia Tunnel.

Railroad tunnel and tracks through mountain.

The entrance of the Shawangunk Tunnel, on the east side.

The entrance of the Shawangunk Tunnel, on the west side.

The Breckneck Tunnel.