The firm was started in 1990 and specializes in HVAC and plumbing design, construction supervision, and energy audits for buildings such as schools (K-12 and higher education), office buildings, churches, medical facilities, commercial, industrial, and mining facilities. Mechanical Design Works(a wholly owned subsidiary of Powder River Heating and A/C) is the only locally owned, licensed, bonded, and insured mechanical engineering firm in Gillette, WY.