Abstract: A mixer for particulate materials, such as soil, dirt, sand, concrete, lime, fertilizers, aggregate, and water, hitched to a skid steer motor vehicle has a bucket for accommodating the particulate materials. A pair of augers having opposite spiral flights located within the bucket are driven by a hydraulic fluid operated motor to mix the particulate materials. The operator of the vehicle controls the hydraulic motor to reverse the rotational direction of the augers to control the mixing of the particulate materials. A door mounted on the side wall of the bucket is movable with a hydraulic cylinder to an open position to allow the particulate materials to be discharged from the bucket.