Swans signal spring's onset: Northbound flocks cacophonously converge on Calispell Lake.

Byline: Mike Prager

Mar. 21--Thousands of graceful, but noisy, tundra swans are on the move through the Inland Northwest, part of a dramatic spring migration that often goes unnoticed because of the birds' preference for isolation.

At Calispell Lake near Usk in Pend Oreille County, large flocks of swans arrived Sunday and are expected to remain about two weeks. Every March, they return to the marshy waterway northeast of Spokane, and from a distance their white bodies form masses of snowy color against a darker backdrop. Their arrival often coincides with…