The 37,000 acre St. Regis Indian Reservation, located astride the U.S.-Canadian border, is home for 5,000 Mohawk Indians. Big cities' Mohawk men are famed for their sure-footed skill as "high-iron" construction wo rkers, builders of skyscrapers and bridges, but back on the reservation life is neither exciting nor well paid, and for years the Indians have been thoroughly ignored by their neighbors in the surrounding small towns of western New York. Most Mohawks living at St. Regis have low incomes and little education , and until recently there seemed faint hope for a better life for their children.