The McMahon Group is a family of companies providing engineering, architectural, design/build and operations services to public and private clients since 1909.  Our companies include:

• Engineering and Architectural Services:   McMahon

• Design / Build Services:                         McMahon, Inc.

• Operations Services:                             Midwest Contract Operations, Inc. (MCO)

Our staff of engineers, architects, technicians, operators and support personnel provide trusted expertise from our office locations in Wisconsin, Illinois and Indiana.