Interstate Mechanical Corp Share: Plumbing, Heating, AC & Refridgeration Interstate Mechanical Corp Visit Website PO Box 1378 Sioux City, IA 51102-1378 (712) 255-1645 (712) 255-0628 (fax) About Rep Info Map About Mechanical Contractor Whom to Contact James Olson What's Nearby? Distance: 5 10 15 20 25 50 mi.