Here's a nice vintage unused postcard from Sault Saint Marie, Michigan, featuring a ship passing through the MacArthur Lock.

The description on the back reads:

"The purpose of the Locks is to overcome the approximately 20-foot difference in level between Lake Superior on the west and Lake Huron on the southeast. Ships in the Locks are raised or lowered by the principles of gravity and water seeking its own level."

It is designated as "Plastichrome" by Colourpicture Publishers, Inc, Boston 15, Mass., U.S.A. and was published by Hiawatha Card Co., of Ypsilanti, Mich. It bears the code P13267.

Size: approx. 3½" x 5½"

Date: Not explicitly dated but appears to me to be from the 1950s; pre-Zip Code, anyway.

Condition: Very good, I'd say, with just some light staining near the right edge on the back, and very faint diagonal impressions across the corners from storage in a standard postcard album. (Please see scans.)

MULTIPLE ITEM SHIPPING DISCOUNT: I will ship up to 4 cards for the single base shipping charge shown. For purchases of more than 4 cards, the shipping charge will increase by just a small increment for every 4 additional cards.