The International Union of Operating Engineers (IUOE) is a progressive, diversified trade union that primarily represents operating engineers, who work as heavy equipment operators, mechanics, and surveyors in the construction industry, and stationary engineers, who work in operations and maintenance in building and industrial complexes, and in the service industries. IUOE also represents nurses and other health industry workers, a significant number of public employees engaged in a wide variety of occupations, as well as a number of job classifications in the petrochemical industry.

Tower Rock Stone Company Inc is a construction company based out of 250 W Sand Bank Rd, Columbia, Illinois, United States.

The Missouri State Employees'​ Retirement System (MOSERS), established September 1, 1957, is governed by the statutes of the state of Missouri. MOSERS is a statewide public pension fund providing retirement, disability and survivor benefits for approximately 100,000 state employees, retirees, and their families.

Interactive Management, Inc. (IMI) is a full service accredited association management company. Association management companies enable all organizations to enjoy the benefits of professional management. At IMI, we work as a team to ensure the value and success of our client's programs. Our role is to manage the activities of our clients and help them realize their goals and objectives with the guidance of their board of directors. This allows volunteers to concentrate on program development, not administrative detail.

Kilian Engineering, Inc specializes in mechanical, electrical, plumbing and fire alarm engineering and design.

An experienced Midwest specialty contractor focused on Transportation, Safety, and Site Development. Our work includes guardrails, signage, civil construction, fencing, and metal fabrication. Today in 2023 we are celebrating 50 years in business.

Headquartered in Bridgeton, MO, Byrne & Jones Construction is one of the largest commercial pavers in the Midwest. With locations in Illinois, Kansas, Missouri, Nebraska, and Ohio, Byrne & Jones Construction includes several divisions and owned subsidiaries that focus on commercial asphalt paving, commercial concrete, sports construction, parks construction, stabilization, engineering & design, and micro-surfacing. We are in the business of exceeding our client's expectations by combining our experienced team with the latest technology and equipment to get the job done right – on time and within the budget. While specializing in creating solutions to our client's toughest challenges, we bring 45+ years of experience to the job. Our family of companies provide construction services including soil stabilization, paving services, track and field construction, tennis & pickleball courts, concrete flatwork. No matter which of our services you are interested in, we have a committed team to build and maintain your surfaces long-term. To learn more, visit our website at www.byrneandjones.com.

Christ Brothers Asphalt Inc is a construction company based out of P.O. BOX 158, Lebanon, Illinois, United States.

Lionmark Construction Companies, LLC is located in St. Louis, Missouri, United States. Our family of companies has been providing construction and material services for infrastructure projects throughout the Midwest since 1932 and continue to be an innovative, dynamic, driving force in the construction industry. We are recognized for excellence in safety, quality, and customer satisfaction thanks to our team's commitment to building and maintaining highways/bridges, manufacturing asphalt, supplying asphalt emulsions/sealers, and producing aggregates for construction.

General Contracting Commercial Construction Utilities Drilling Excavation

J.H. Berra Construction Co., Inc. is a construction company based out of 5091 NEW BAUMGARTNER RD, Saint Louis, Missouri, United States.

Highway and bridge construction.