In 1898, Mr. David T. Hanbury tried to reach the unexplored tract between Chesterfield inlet and Great Slave lake via the Norway-House—York-Factory—Churchill route. Finding that he arrived too late at the latter place, he decided to spend the summer on the Hudson bay coast and make preparations for an early start the following year. In 1899, he made an interesting trip from Churchill to Great Slave lake via Chesterfield inlet, Thelon and Ark-i-linik rivers, Clinton-Colden and Artillery lakes, and Lockhart river. As he was the first white man to explore Ark-i-linik or Thelon river, its most western affluent has since been called Hanbury river. In 1901, Mr. Hanbury travelled from Edmonton to Depot island in the northern part of Hudson bay, via Fort Resolution, Great Slave lake, Artillery lake, Hanbury, Thelon and Dubawnt rivers, Baker lake, Chesterfield inlet and Marble island. He spent most of the winter in an Esquimaux camp near Baker lake, and in February started on an adventurous trip back to civilization via Aberdeen lake and Thelon river, thence overland to Buchanan river, down that stream to Backs river, thence to the coast, westward along the coast to the mouth of the Coppermine, up the Coppermine to Kendall river, via Dismal lake, Dease river, Great Bear lake and Great Bear river to Fort Norman. Mr. Hanbury gives an interesting account of these trips in his book “Sport and Travel in the Northland of Canada.” The United States Biological Survey, in the early spring of 1901, determined to send Mr. Edward A. Preble, Assistant of the Survey and one of its trained field naturalists, to obtain representative collections of the mammals, birds and plants of the great interior region west of Hudson bay drained mainly by the Mackenzie and described in the reports of the Survey as the most neglected large area in North America. As it was evident that only part of the region could be examined satisfactorily in a single season, it was determined to make first a reconnaissance of the region about Athabaska and Great Slave lakes. The route followed by Mr. Preble’s party was via Great Slave lake, including the north arm, to Fort Rae; the chain of lakes and rivers by way of Lake St. Croix to MacTavish bay; Great Bear lake and Great Bear river to the Mackenzie. It had been the intention of Mr. Preble, who was accompanied by his brother and Mr. James MacKinley, formerly of the Hudson’s Bay Company, to cross by one of the Indian routes to the upper Coppermine and to descend that stream, but various circumstances rendered this impossible and he was obliged to take the shorter and more westerly route.