Borings (3 of 7)

Concrete boring 22-16A  80.8 Ft to 100 Ft and 17-G21  3.3 Ft to 44 Ft, Electronic reproduction of photograph.  The Mackinac Bridge 1954 - 1958. Mackinac Bridge Authority
Abstract/Description: Concrete boring 22-16A 80.8 Ft to 100 Ft and 17-G21 3.3 Ft to 44 Ft
Subject(s): Bridges--Design and construction
St. Ignace (Mich.)
Mackinaw City (Mich.)
Mackinac Bridge (Mich.)
Date Created: 1955 (approximate)