Midwestward ho!

WHEN fans and alumni sing the University of Michigan's fight song, they still hail the Wolverines as the ``champions of the West.'' Michigan's fierce burrowing beasts, the wolverines, have all but retreated into history, as the state's forests were cleared by lumbering and as city folk increasingly colonized the North Woods. And the state's identity as one of the Northwest Territories is recorded mainly on maps in history texts. Surely Michigan now is ``Midwestern'' -- part of the industrial, agricultural, recreational Midwest. Or is it?

The locus of the American Middle West, the heartland, has apparently shifted to a region centering on Omaha and Lincoln, Neb., says James R. Shortridge of the University of Kansas, a geography professor. It tightly embraces the Great Plains states of Nebraska, Iowa, Kansas, South Dakota, and Missouri. Professor Shortridge's study was based partly on definitions of the ``vernacular'' Middle West as perceived by college youths in 32 states. The survey indicated the eastern part was no longer included.

Agencies and scholars have often defined the Middle West as a 12-state region, from Ohio and Michigan in the east across to the Dakotas and down to Kansas. Botanical maps picture the states as united by prairie, which shows up in patches as far east as Pennsylvania.

But sharing a common topography has failed to give the Middle West -- a concept as much a place -- a sense of community to those who live there: Iowans and Kansans have long thought of Ohioans and Michiganders as Easterners; eastern Midwesterners have considered Dakotans and Nebraskans as residents of the Western frontier.

Geography alone has thus had a hard time keeping the Middle West put. The heartland's continental drift reflects the Western spread of population, as the locus of American population moves steadily toward the Rockies.

However, while the ``heartland'' may be approaching the steppes of the great divide, the statistical population center has only recently just crossed the Mississippi, south of St. Louis. When last ``sighted'' by the US Census Bureau, the population center had reached the town of De Soto, in Jefferson County, Mo. -- 47.1 miles west and 22.5 miles south of the 1970 center of population near Mascoutah, Ill.

Politically speaking, Midwestern values have already crossed the Continental Divide. They have become increasingly evident in Sunbelt political life as the result of north-central state labor, production, and retirement dispersal. The New World's westward orientation seems as secure as ever.