CREATE TABLE table_203_839 (id NUMBER, "station" CLOB, "type" CLOB, "latitude" CLOB, "longitude" CLOB, "el.  ( m ) " NUMBER, "opened" NUMBER, "closed" NUMBER, "coordinates" CLOB)

how long did the mount harquahala , arizon station operate ?
SELECT "closed" - "opened" FROM table_203_839 WHERE "station" = 'mount harquahala, arizona'
SELECT "closed" - "opened" FROM "table_203_839" WHERE "station" = 'mount harquahala, arizona'