There are three files to download per quad:
xxxxxx.sdw
xxxxxx.sid
xxxxxx.txt

Click here for DRG's

Click here for DOQQ's
3490A1 CHARLESTON
3490A2 FISHHOOK LAKE
3490A3 VANCE
3490A4 TUTWILER
3490A5 MATTSON
3490A6 DUNCAN
3490A7 ROUND LAKE
3490A8 LACONIA
3490B1 TOCOWA
3490B2 CROWDER
3490B3 LAMBERT
3490B4 SABINO
3490B5 CLARKSDALE
3490B6 SHERARD
3490B7 RENA LARA
3490B8 MELLWOOD
3490C1 ASA
3490C2 CURTIS STATION
3490C3 MARKS
3490C4 JONESTOWN
3490C5 COAHOMA
3490C6 FRIARS POINT
3490C7 ELAINE
3490D1 PLEASENT GROVE
3490D2 CRENSHAW SOUTH
3490D3 FALCON
3490D4 LULA
3490D5 MOON LAKE
3490D6 FRIARS POINT NW
3490E1 LONGTOWN
3490E2 CRENSHAW NORTH
3490E3 WALNUT LAKE
3490E4 DUNDEE
3490E5 HELENA
3490F1 ARKABUTLA EAST
3490F2 ARKABUTLA WEST
3490F3 HOLLYWOOD
3490F4 TUNICA MS
3490F5 STUBBS ISLAND
3490G1 FREES CORNER
3490G2 BANKS
3490G3 ROBINSONVILLE
3490G4 COUNCIL
3490G5 BRICKEYS
3490H1 HORN LAKE
3490H2 LAKE COMORANT
3490H3 HORSESHOE LAKE
3490H4 HUGHES