As a young worker, he was first employed as a civil engineer by various railroads in New York and the Southern United States.

[5] Putnam moved to Eau Claire on May 23, 1857, and became a clerk at the federal land office.

[6] Through his control of this office, Putnam became a powerful force in the Chippewa Valley pinery.

One of the most successful land agents and promoters in the area, his knowledge of the Chippewa pine lands brought him the business of lumbermen like Frederick Weyerhaeuser and pine-land dealers like Henry W. Sage and Cornell University.

[7][8] Although his dream of a pool to monopolize the timber lands of the Chippewa went unrealized, Putnam acquired a considerable fortune through his promotions.