Colonel Macomb never lived in St. Paul but supervised the office from Rock Island, where he was engaged in improving the Des Moines and Rock Island Rapids. During Macomb’s tenure, Franklin Cook, a civilian engineer, managed the work of the District. Most of Cook’s time was devoted to the preservation of St. Anthony Falls and to supervising the dredging and snagging on the Mississippi, Wisconsin, and Minnesota Rivers to maintain a 3-½ foot navigation channel.