CREATE TABLE table_47379 ("Rank" FLOAT, "Mountain Peak" TEXT, "Region" TEXT, "Mountain Range" TEXT, "Location" TEXT)

what is the rank when the mountain peak is isthmus peak?
SELECT "Rank" FROM table_47379 WHERE "Mountain Peak" = 'isthmus peak'
SELECT "Rank" FROM "table_47379" WHERE "Mountain Peak" = 'isthmus peak'