CREATE TABLE table_45509 ("Pinnacle height" TEXT, "Year" FLOAT, "Structure type" TEXT, "Main use" TEXT, "Country" TEXT, "Town" TEXT)

What is the main use of the structure that was in redfield, arkansas before 2004?
SELECT "Main use" FROM table_45509 WHERE "Year" < '2004' AND "Town" = 'redfield, arkansas'
SELECT "Main use" FROM "table_45509" WHERE "Town" = 'redfield, arkansas' AND "Year" < '2004'