10 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
EXPLORATIONS AND RESEARCHES. 
STUDY OF OLDER SEDIMENTARY ROCKS. 
During the past twenty years I have been studying the older sedi- 
mentary rocks of the North American Continent from Newfoundland 
to Alabama on the eastern side and from southeastern California to 
northern Montana on the western. In the interior, east of the Rocky 
Mountains, studies were carried on in Texas, South Dakota, Minne- 
sota, and Wisconsin. 
Three important sections remained to be examined—one of the 
Lower Cambrian in western Nevada, one in northern Montana, and 
another of the lower Paleozoic Rocks of the main range of the Rocky 
Mountains in the vicinity of the Canadian Pacific Railroad. 
The latter was selected for examination during the field season of 
1907, and although the work did not begin until after the close of the 
fiscal year I will here briefly recount some of its results. Early in 
July, a camp outfit was secured at Field, British Columbia, and work 
begun on Mount Stephen. Subsequently sections were studied and 
measured at Castle Mountain, west of Banff, Alberta; at Lake Louise, 
south of Laggan, Alberta, anal on Mount Bosworth on the Conti- 
nental Divide near Hector, British Columbia. 
Upwards of 20,000 feet of strata were carefully examined and 
measured, and collections of fossils and rocks made from many locali- 
ties. It was found that the Cambrian section included over 12,000 
feet of sandstones, shales, and limestones, and that the three great 
divisions of the Cambrian—the Lower, Middle, and Upper—were 
represented in the section of Bow River series and the Castle Moun- 
tain group. Characteristic fossils were found in each division. 
ALASKAN EXPEDITION. 
In continuation of work already satisfactorily begun, the Secretary 
authorized, in April of the present year, an expedition for the col- 
lection of the remains of large extinct vertebrates, particularly mam- 
mals, in Alaska. Although fragmentary materials have been se- 
cured there from time to time by various exploring parties and 
mining expeditions, the country is still, to a considerable extent, a 
virgin field, and the recent great development of the mining industry 
makes the present time particularly favorable for the work proposed, 
especially on account of the facilities for transportation thus rendered 
available. 
_ The expedition has been placed in charge of Mr. C. W. Gilmore; a 
member of the staff of the National Museum, who will have the serv- 
ices of a guide trained in the methods of the work to be accomplished 
and thoroughly familiar with the regions to be explored. 
