A hydraulic lift arm assembly includes a lift arm, a lift cylinder raising and lowering the lift arm, a lift arm stop, and a stowing mechanism. The stowing mechanism automatically retains the lift arm stop in a stowed position in response to the lift arm stop moving into the stowed position. The lift arm stop is movable into a locked position in which the stop resists substantial actuation of the lift cylinder from an extended condition, and thereby resists substantial lowering of the lift arm from a raised position. The lift arm stop may include a slot and pin arrangement to permit linear and pivotal movement of the stop with respect to the lift arm. The linear movement may provide clearance for a tongue on the stop to pivot past a portion of the lift cylinder as the stop is moved into the locked position.