Headquartered in Laramie, Wyoming, Trihydro provides environmental consulting, engineering and surveying, air quality and pro ... cess management, information technology, and water and natural resource services to public and private clients. Trihydro is also the largest HUBZone contractor in the continental U.S. under NAICS 562910. From its initial startup as a two-person firm in 1984, Trihydro has grown into a successful organization of nearly 500 employees with 21 offices and support staff nationwide. Phone number: 1.307.745.7474 www.trihydro.com read more