Being a Government scout, Mr. Denig was able to conciliate the Indians during the expedition of Audubon in 1843, making it possible for the great Frenchman to collect his wonderful specimens. A very colorful description of Fort Union was written by Mr. Denig July 30, 1843. This description is found in Volume II, page 180, of “Audubon and His Journals.” In it Mr. Denig writes: “Fort Union, the principal and handsomest trading post on the Missouri River, is situated on the north side, about 6½ miles above the mouth of the Yellowstone River; the country around it is beautiful and well chosen for an establishment of the kind.” Then after describing in detail the structure and furnishings of the fort, he says: “The principal building in the establishment, and that of the gentleman in charge, or bourgeois, is now occupied by Mr. Culbertson, one of the partners of the company,” and farther on, “Next to this is the office, which is devoted exclusively to the business of the company. * * * This department is now under my supervision [viz., E. T. Denig].” During this period Audubon sojourned with him for some time and spoke of him not only as an agreeable companion but also as a friend who gave him valuable information and enthusiastic assistance. One of his frequent companions at Fort Union was the Belgian priest, Father De Smet. Their correspondence was continued after De Smet had returned to Belgium. (See Life, Letters and Travels of Father De Smet, Chittenden and Richardson, 4 vols., New York, 1905.)