MATHIASEN’S TANKER INDUSTRIES INC.
image by Joe McMillan, 29 October 2001
image by Ivan Sache, None
Brown 1958 shows a flag with a black band at the top, matching the red, black-topped funnel and white M. Rosanoski considers this possible, while noting evidence for a plain-red flag instead.
The alternative flag is red with a white M. Later blue or grey funnels carried a red band and white M, supporting the plain flag design; it probably also applies to the Prairie Grove variants.
Prairie Grove is recorded with M237, changing to M238 by the New York sighting of October 1973.