On December 30, 1995, at 1315 mountain standard time, a Bellanca 17-30, N7356V, departed the side of the runway during landing at La Plata County Airport, Durango, Colorado. The CFI and student pilot were not injured and the aircraft sustained substantial damage. Visual meteorological conditions prevailed for this Title 14 CFR Part 91 local area instructional flight and no flight plan was filed. According to the flight instructor, the owner/student was performing touch-and-go landings and the landing which preceded the accident was smooth and on center line. The flight instructor said that when the nose wheel was lowered to the runway, the aircraft immediately veered to the right. He said he got on the rudder with the student and had full left rudder applied without effect. As the aircraft departed the side of the runway the landing gear collapsed in the rough terrain and the aircraft slid to a stop. There was no fire. Examination of the aircraft provided evidence of a fractured left nose wheel steering rod. Examination of the rod provided evidence that the rod fractured at the adjustment nut. According to the attached metallurgist's report, the fracture surface exhibited features typical of an overstress separation.