Abstract: A narrow profile, variable width stump grinder comprising a stump treatment tool adapted to forcibly grind a stump and a variable width carriage. The carriage comprises a rigid elongated frame and independently driven wheels coupled to the frame by extensible axles or struts. The frame comprises a longitudinal central member terminating in a header supporting the tool and a front tongue adapted to be coupled to a tow vehicle. The retractable struts are oriented generally perpendicularly to the longitudinal axis of the machine. The header comprises a housing defining parallel sleeves oriented perpendicularly to the axis to receive the struts. A hinged stand is pivotally secured to the top of the header to support the treatment tool in a raised position for transport. A linkage interconnecting the struts and a hydraulic cylinder deploys or retracts the struts to widen or narrow the grinder's stance. The linkage comprises an L-shaped crank pivoted to the frame.