Keep the Green Light Burning Sign at Mackinac Bridge Construction Site

This sign is a safety reminder to everyone involved in building the Mackinac Bridge., Electronic reproduction of text.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: This sign is a safety reminder to everyone involved in building the Mackinac Bridge.
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1957 (approximate)