CREATE TABLE table_1637981_7 (kalamazoo__azo_ VARCHAR, saginaw__mbs_ VARCHAR)

What is the fare to Kalamazoo during the time frame when Saginaw's was $481.39?
SELECT kalamazoo__azo_ FROM table_1637981_7 WHERE saginaw__mbs_ = "$481.39"
SELECT "kalamazoo__azo_" FROM "table_1637981_7" WHERE "$481.39" = "saginaw__mbs_"