CREATE TABLE table_63446 ("Locks & Dam" CLOB, "Location [L ]" CLOB, "River Mile" FLOAT, "Lock Side" CLOB, "Lock Lift/Drop  ( in feet ) " CLOB, "Pool Length  ( miles ) " CLOB)

What is the River Mile with a RDB lock side and a pool length of 55.4?
SELECT "River Mile" FROM table_63446 WHERE "Lock Side" = 'rdb' AND "Pool Length (miles)" = '55.4'
SELECT "River Mile" FROM "table_63446" WHERE "Lock Side" = 'rdb' AND "Pool Length (miles)" = '55.4'