Agate Construction is a unique, diverse company specializing in both heavy highway and marine construction. Many well-respected contractors do one or the other, but rarely do both with our success rate. Agate is a family owned business founded in 1981 and completes approximately $35M of work annually for federal, state, municipal, and private owners. We are known for and excel in: bridge construction, highway construction, deep foundations and cofferdams, jetties, piers, site work, and utility construction.