Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the highest River Mile that has a pool length of 42.2 miles or a lock/lift drop of 21 feet?

### Inputs:
table_name: table, columns: ['Locks & Dam', 'Location [L ]', 'River Mile', 'Lock Side', 'Lock Lift/Drop (in feet)', 'Pool Length (miles)']

### Response:
SELECT MAX River Mile FROM table WHERE Pool Length (miles) = 42.2 AND Lock Lift/Drop (in feet) = 21