Kathy Gunn, age 12, of Lakewood, Ohio, for her question:

How long is the Soo Canal?

There are two Soo Canals, one on the Canadian side of the St. Mary River and one on the American side. The American Soo Canal is 7.6 miles long. It has four locks ringing from 77 to 31 feet in depth, 60 to 95 feet in width, and 70 feet to 1,30 feet in length. The Canadian Soo is 1.4 miles long and its one lock is 60 feet wide and 900 feet long. Both canals are duty‑free.

The full name of the Soo Canals is the Sault Sainte Marie Canals. Sault Sainte Marie was named by Jesuit Missionaries way back in 1641. It means the Rapids of St. Mary. The St. Mary River is a tumbling, 63‑mile stream which drains the waters of Lake Superior into Lake Huron. Lake Superior is 22 feet higher than Lake Huron and the river makes this drop in a series of gurgling rapids.