Abstract: A locking mechanism for a retractable cargo bed includes an engagement rail forming part of a stationary frame; the engagement rail having a top edge profile defining a plurality of locking recesses. A locking member carried by a travelling frame and adapted to engage a selected locking recess of the plurality of locking recesses. A spring adapted to bias the locking member into engagement with the selected locking recess. An activation lever adapted to permit a user to overcome the biasing force of the spring to disengage the locking member from the selected locking recess.