Snow geese take flight over the 164-mile-long (264-kilometer-long) St. Croix River. Separating Minnesota and Wisconsin before emptying into the Mississippi River, the St. Croix and its tributary the Namekagon were among the first rivers to be protected by the 1968 Wild and Scenic Rivers Act, a Congressional decree which guarantees these rivers will not be industrialized, dammed, or developed.

(Text adapted from and photograph shot on assignment for, but not published in, "Our Wild and Scenic Rivers: The St. Croix ," July 1977, National Geographic magazine)