CREATE TABLE table_6870 ("Institution" TEXT, "Location" TEXT, "Affiliation" TEXT, "Enrollment" FLOAT, "Mascot" TEXT, "Colors" TEXT)

What Public Institution is in Black River Falls?
SELECT "Institution" FROM table_6870 WHERE "Affiliation" = 'public' AND "Location" = 'black river falls'
SELECT "Institution" FROM "table_6870" WHERE "Affiliation" = 'public' AND "Location" = 'black river falls'