EMCOR Group, Inc. provides construction and facilities, building, and industrial services in the United States and the United Kingdom. It offers design, integration, installation, start-up, operation, and maintenance services related to power transmission, distribution, and generation systems; energy solutions; premises electrical and lighting systems; process instrumentation; low-voltage systems; voice and data communications systems; roadway and transit lighting, signaling, and fiber optic lines; computerized traffic control systems, and signal and communication equipment; heating, ventilation, air conditioning, refrigeration, and geothermal solutions; clean-room process ventilation systems; fire protection and suppression systems; plumbing, process, and high-purity piping systems; controls and filtration systems; water and wastewater treatment systems; central plant heating and cooling systems; crane and rigging services; millwright services; and steel fabrication, erection, and welding services. The company also provides building services that covers commercial and government site-based operations and maintenance; facility management, maintenance, and services; energy efficiency retrofit services; military base operations support services; services for indoor air quality; floor care and janitorial services; landscaping, lot sweeping, and snow removal services; vendor management and call center services; installation and support for building systems; program development, management, and maintenance for energy systems; technical consulting and diagnostic services; infrastructure and building projects; modification and retrofit projects; and other building services, including reception, security, and catering services. In addition, it offers refinery turnaround planning and engineering; welding; overhaul and maintenance; instrumentation and electrical; and renewable energy services. The company was incorporated in 1987 and is headquartered in Norwalk, Connecticut.

MasTec, Inc., an infrastructure construction company, provides engineering, building, installation, maintenance, and upgrade services for communications, energy, utility, and other infrastructure primarily in the United States and Canada. It operates through five segments: Communications, Clean Energy and Infrastructure, Oil and Gas, Power Delivery, and Other. The company build infrastructure for wireless and wireline/fiber communications; clean energy infrastructure comprising renewable energy power generation; pipeline infrastructure, including natural gas, water, carbon capture sequestration, and other product transport; power delivery services, such as electrical and gas transmission, and distribution systems; industrial and heavy civil infrastructure, including roads, bridges, and rail; and water infrastructure. It also installs electrical and other gas distribution and transmission systems, power generation, power generation, civil and industrial facilities, pipelines, and fiber optic and other cables, as well as install-to-the-home services. In addition, the company offers maintenance and upgrade support services comprising maintenance of customers' distribution facilities, networks, and infrastructure, including communications, power generation, pipeline, electrical distribution and transmission, and civil and industrial and heavy civil infrastructure; service restoration for natural disasters and accidents; and routine replacements and upgrades to overhauls. Its customers include wireless and wireline/fiber service providers, broadband operators, install-to-the-home service providers, public and private energy providers, including renewable and other energy providers, pipeline operators, civil and industrial infrastructure providers, and government entities. MasTec, Inc. was founded in 1929 and is headquartered in Coral Gables, Florida.

Knife River Corporation, together with its subsidiaries, provides aggregates- led construction materials and contracting services in the United States. It operates through Pacific, Northwest, Mountain, Central, and Energy Services segments. The company mines, processes, and sells construction aggregates, including crushed stone and sand, and gravel; and produces and sells asphalt and ready-mix concrete. It also provides contracting service, such as heavy-civil construction, asphalt and concrete paving, and site development and grading. In addition, the company sells cement, merchandise, and other building materials and related services. The company sells its construction materials to public and private-sector customers, including federal, state, and municipal governments, as well as industrial, commercial and residential developers, and other private parties; and provides its contracting services to public-sector customers for the development and servicing of highways, local roads, bridges, and other public-infrastructure projects. Knife River Corporation was founded in 1917 and is based in Bismarck, North Dakota.

NorthWestern Energy Group, Inc. provides electricity and natural gas to residential, commercial, and various industrial customers. It generates, purchases, transmits, and distributes electricity; and produces, purchases, stores, transmits, and distributes natural gas, as well as owns municipal franchises to provide natural gas service in the communities. The company operates 6,600 miles of electric transmission and 18,674 miles of electric distribution lines with approximately 395 transmission and distribution substations; and 2,235 miles of natural gas transmission and 5,155 miles of natural gas distribution lines with approximately 133 city gate stations in Montana. It also operates 1,310 miles of electric transmission and 2,365 miles of electric distribution lines in South Dakota with approximately 124 transmission and distribution substations; and 55 miles of natural gas transmission and 2,573 miles of natural gas distribution lines in South Dakota and Nebraska. The company provides electricity and/or natural gas to approximately 775,300 customers in Montana, South Dakota, Nebraska, and Yellowstone National Park. NorthWestern Energy Group, Inc. was founded in 1923 and is based in Sioux Falls, South Dakota.

MDU Resources Group, Inc. engages in the regulated energy delivery, and construction materials and services businesses in the United States. It operates through four segments: Electric, Natural Gas Distribution, Pipeline, and Construction Services. The Electric segment generates, transmits, and distributes electricity for residential, commercial, industrial, and municipal customers in Montana, North Dakota, South Dakota, and Wyoming; and operates 3,400 miles of transmission lines, 4,800 miles of distribution lines, and 82 transmission and 298 distribution substations. The Natural Gas Distribution segment distributes natural gas for residential, commercial, and industrial customers in Idaho, Minnesota, Montana, North Dakota, Oregon, South Dakota, Washington, and Wyoming; and supplies related value-added services. The Pipeline segment provides natural gas transportation and underground storage services through a regulated pipeline system primarily in the Rocky Mountain and northern Great Plains regions; and cathodic protection and other energy-related services. The Construction Services segment offers electrical and mechanical contracting services, including the construction and maintenance of electrical and communication wiring and infrastructure, fire suppression systems, mechanical piping, and services; transmission and distribution contracting services, comprise construction and maintenance of overhead and underground electrical, and gas and communication infrastructure; and manufactures and supplies transmission and distribution lines construction equipment and tools. It serves manufacturing, commercial, industrial, transportation, institutional, and renewable and government customers, as well as utilities. MDU Resources Group, Inc. was incorporated in 1924 and is headquartered in Bismarck, North Dakota.

Primoris Services Corporation, a specialty contractor company, provides a range of specialty construction, fabrication, maintenance, replacement, and engineering services in the United States and Canada. The company operates through Utilities and Energy/Renewables segments. The Utilities segment offers installation and maintenance services for new and existing natural gas distribution systems, electric utility distribution and transmission systems, and communications systems. The Energy/Renewables segment provides a range of services, including engineering, procurement, and construction, as well as retrofits, highway and bridge construction, demolition, site work, soil stabilization, excavation, flood control, upgrades, repairs, outages, and maintenance services to renewable energy and energy storage, renewable fuels, petroleum, and petrochemical industries, as well as state departments of transportation. It also offers pipeline construction and maintenance, and storage services; pipeline facility, and integrity services. Primoris Services Corporation was founded in 1960 and is headquartered in Dallas, Texas.

MYR Group Inc., through its subsidiaries, provides electrical construction services in the United States and Canada. It operates in two segments, Transmission and Distribution, and Commercial and Industrial. The Transmission and Distribution segment offers a range of services on electric transmission and distribution networks, and substation facilities, including design, engineering, procurement, construction, upgrade, maintenance, and repair services with primary focus on construction, maintenance, and repair to customers in the electric utility industry; and services, including construction and maintenance of high voltage transmission lines, substations, and lower voltage underground and overhead distribution systems, clean energy projects, and electric vehicle charging infrastructure services, as well as emergency restoration services in response to hurricane, wildfire, ice, or other related damages. This segment serves as a prime contractor to customers, such as investor-owned utilities, cooperatives, private developers, government-funded utilities, independent power producers, independent transmission companies, industrial facility owners, and other contractors. The Commercial and Industrial segment provides a range of services, including design, installation, maintenance, and repair of commercial and industrial wiring; and installation of intelligent transportation systems, roadway lighting, and signalization for airports, hospitals, data centers, hotels, stadiums, commercial and industrial facilities, clean energy projects, manufacturing plants, processing facilities, water/waste-water treatment facilities, mining facilities, intelligent transportation systems, roadway lighting, signalization, and electric vehicle charging infrastructure. This segment serves general contractors, commercial and industrial facility owners, governmental agencies, and developers. The company was founded in 1891 and is headquartered in Thornton, Colorado.

Energy Services of America Corporation, together with its subsidiaries, provides contracting services for utilities and energy related companies in the United States. The company constructs, replaces, and repairs interstate and intrastate natural gas pipelines and storage facilities for utility companies and private natural gas companies; and provides services relating to pipeline, storage facilities, and plant works. It also offers electrical and mechanical installation, and repair services, including substation and switchyard, site preparation, equipment setting, pipe fabrication and installation, packaged buildings, transformers, and other ancillary works for the gas, petroleum power, chemical, water and sewer, and automotive industries. In addition, the company provides corrosion protection services, horizontal drilling services, liquid pipeline and pump station construction, production facility construction, water and sewer pipeline installation, and various maintenance and repair services, as well as other services related to pipeline construction. Further, it serves customers primarily in West Virginia, Virginia, Ohio, Pennsylvania, and Kentucky. Energy Services of America Corporation was incorporated in 2006 and is based in Huntington, West Virginia.