The muon detection system for the Fermilab D∅ detector is described. It has better muon detection performance than other existing hadron collider detectors, with respect to both hadron attenuation length and position resolution. In the large angle region there are three large magnetized toroids and a total of 10 planes of proportional drift tube chambers made of 10 cm wide cells. At both small angles there are magnetized toroids and 9 planes of proportional drift tubes made of 3 cm diameter stainless steel tubes. The 10 cm wide cell structure is made of specially designed aluminum extrusions, which make the assembly of a whole chamber easy. The chamber is provided with vernier pads so that the position of a charged particle can be simultaneously detected in both directions perpendicular and parallel to the sense wire. The system resolution goal along the wire is ±2.0 mm and perpendicular to the wire ±0.5 mm.