High Quality Content by WIKIPEDIA articles! The Chevrolet Avalanche is a four-door, five or six passenger sport utility truck sharing GM`s long-wheelbase chassis used on the Chevrolet Suburban and Cadillac Escalade EXT. Unlike the typical pickup truck, the open bed of the Avalanche opens to the back seat area through a folding panel (marketed as a `mid-gate`) and a removable rear window. A series of three removable panels form a watertight cover for the cargo bed. Additional storage is provided behind each wheel well, accessed by locking flip-top panels and usable as self-draining ice chests.