Tri-Boro Trailer was acquired by Mr. John, Inc., in 1964 and sold to The Holden Corporation in 1985. Headquartered with Mr. John in Pittsburgh's Lawrenceville neighborhood, Tri-Boro Trailer's rental fleet then consisted of more than 130 40-foot storage trailers. The company's focus was to provide the best service possible as well as a complimentary product line to portable toilet customers.

Tri-Boro relocated to Neville Island in 1992 and decided to purchase six mobile office trailers and diversify its product line. The office trailer rental business remained a relatively small focus during the company's tenure at the Neville Island location due to the acquisition of Dear John, Inc.'s portable restroom rental business. By the time Tri-Boro had relocated to its current home in Stowe Township, the overall trailer fleet had been reduced to less than 60 office and storage trailers, due to unit sales. Upon relocating to the new facility, however, many of the constraints placed on Tri-Boro Trailer and Mr. John were alleviated, creating new opportunities for expansion.

Currently Mr. John and Tri-Boro Trailer employ more than 55 people and offer a wide range of products including portable toilets, office trailers, and storage containers. Tri-Boro Trailer's fleet includes a variety of 8-foot wide, 10-foot wide, and 12-foot wide trailers, as well as ground-level storage containers for rental or purchase. In addition to inventory fleet, Tri-Boro can design-build custom office trailers, toilet trailers, shower trailers, and change rooms to customer specifications. Tri-Boro Trailer continues to focus on offering a diverse product line and strives to provide the highest level of customer service.

"When quality service counts, call the professionals."