Mr. Gronquist, a specialist in bridge design, was a former partner and consultant of Steinman Boynton Gronquist & Birdsall, a consulting engineering firm in Manhattan. He joined the firm in 1927 after graduating from Rutgers University with a degree in civil engineering. He was named a partner in 1960 and was a managing partner from 1971 to 1976. Afterward, he was a consultant to the firm.
Some Notable Bridges Carl designed include the Mackinac Straits Bridge in Michigan, the Kingston-Rhinecliff Bridge over the Hudson River, as well as the famed Golden Gate Bridge, the Henry Hudson Bridge, and the Sault Ste. Marie International Bridge.
He was one of the earliest men to earn a Civil Engineering license in the United States.
https://www.bpelsg.ca.gov/pubs/num_eng_82.pdf
https://www.newspapers.com/article/statesman-journal/163582337/