The facts to be presented here were gathered during the summer of 1906, while undertaking a rapid geologic reconnaissance in the region northeast of Cook inlet, Alaska.
Cook inlet occupies a broad indentation on the western side of the gulf of Alaska. The region explored is drained by two rivers—the first, the Matanuska, emptying into Knik arm at the head of Cook inlet; the second, Sushitna river, emptying into Cook inlet proper. Though portions of the region have been visited at various times in the past by Eldridge,‡ Mendenhall,§ and Martin,|| much of the area is unknown. A notable development of Jurassic and Tertiary sediments and the presence of workable commercial coal in such a remote district seem of sufficient importance to warrant the presentation of the following facts:
An attempt will be made to give a brief statement of the stratigraphic succession . . .