A snowmobile frame includes a tunnel, the tunnel includes a left structure having a front portion and a rear portion, a right side structure having a front portion and a rear portion, a radiator interconnecting the rear portion and the left side structure with the rear portion of the right side structure, and an engine cradle forward of the tunnel. The engine cradle includes a front wall connecting the front portion of the left side structure and the front portion of the right side structure, a rear wall interconnecting the left side structure and the right side structure, and a bottom plate intermediate the front wall and the rear wall and interconnecting the left side structure with the right side structure. A snowmobile including the snowmobile frame includes an engine and a fastener passing through a hole in one of the left side structure and the right side structure to fasten the engine thereto.