A pneumatically operated vertical clam shell mud bucket attaches to a pipe joint connection in a drill stem on a drilling rig, the mud bucket defining a first tubular section forming a half cylinder hingably attaching a second tubular section forming a mirror image half cylinder, the tubular sections forming a sealed cylinder which is forcibly closed together by a plurality of pneumatic cylinders with a composition compression material forming a liquid seal between the closed half cylinders containing drilling fluids during the drilling stem separation and connection diverting drilling fluids to an outer evacuation hose to an external recirculating system on the drilling rig.