A new 2025 ranking highlights the 57 largest general contractors based in Jefferson County, with firms ordered by their estimated current number of employees. The list reveals a strong presence of companies across a range of construction sectors, from infrastructure and industrial to residential building.
Leading the pack is FlatironDragados USA – Colorado, employing an estimated 3,807 workers, according to LinkedIn. The Broomfield-based heavy civil infrastructure firm, formerly Flatiron Construction Corp., underwent a major reorganization in July 2024 when ACS Group and its subsidiary Hochtief merged their North American units, Flatiron and Dragados, into a single entity. Now operating as FlatironDragados, the company is jointly owned by ACS (61.8%) and Hochtief (38.2%) and continues to operate out of Broomfield.
Also based in Broomfield, MWH Constructors Inc., which focuses on water and sewer line construction, ranks second with 651 employees. Peak Utility Services Group Inc., another Broomfield firm, comes in third with 514 employees.
The top 57 companies reflect a diverse construction landscape in the county. Of those ranked, 21 focus on new single-family housing construction, 11 specialize in industrial buildings, 9 operate in heavy and civil engineering, and 8 are dedicated to highway, street, and bridge construction.
Several smaller firms reported notable workforce growth. PRQ LLC, based in Golden, saw a 66.7% increase in staff, growing from 9 to 15 employees. KLM Construction Inc. in Lakewood increased its workforce by 27.8%, rising from 18 to 23 employees.
Employee figures were drawn from the most recent U.S. Department of Labor Form 5500 filings or LinkedIn estimates, offering a snapshot of the construction industry’s workforce footprint across Jefferson County.
