CREATE TABLE table_68077 ("Week" FLOAT, "Date" CLOB, "Visiting Team" CLOB, "Final Score" CLOB, "Host Team" CLOB, "Stadium" CLOB)

Who was the visiting team on weeks under 12 and at Sports Authority Field at Mile High?
SELECT "Visiting Team" FROM table_68077 WHERE "Week" < '12' AND "Stadium" = 'sports authority field at mile high'
SELECT "Visiting Team" FROM "table_68077" WHERE "Stadium" = 'sports authority field at mile high' AND "Week" < '12'