Field notes on birds observed in Dakota and Montana along the forty-ninth parallel during the seasons of 1873 and 1874

The following notes result from observations made in the field during my connection with the United States Northern Boundary Commission_ Archibald Campbell, Esq., Commissioner, Major W.J Twining, Corps of Engineers, U.S.A. Chief Astronomer.  The line surveyed by the Commission in 1873 and 1874 extended from the Red River of the North to the Rocky Mountains, a distance of 850 miles, along the northern border of the Territories of Dakota and Montana, in latitude 49° north.