ALASKA. 41 
over the Territory, to determine the location and outlines of new areas 
of economic importance, and eventually to obtain complete geologic 
and geographic knowledge; the second embraces the reconnaissance 
mapping of regions of known mineral production; the third consists 
of detailed examinations and surveys of mining districts. 
The months from May to September are usually employed in field 
work. The parties are each placed in charge of the senior geologist or 
topographer, and have varied in size from 3 to 15 men. The methods 
pursued are those which experience has demonstrated will give greatest 
mobility to the parties and most quickly attain the results desired. In 
this work there has been trained a group of men, including geologists, 
topographers, and camp men, who are especially fitted to contend with 
the conditions confronting the Alaskan explorer. 
The transportation of equipment and provisions for an entire season 
becomes a most important factor in the operations of a survey party. 
Some of the journeys have been performed on foot, and the method 
of transportation has been the most primitive of all — that of packing 
the outfit on the backs of men. When a navigable stream was 
reached a framework of spruce and willow was built, the pack covers 
were stretched upon it and smeared with pitch, and the journey was 
continued by canoe or improvised raft. Some of the trips have 
been along the main-stream valleys, where the light cedar canoe has 
been the favorite means of transportation, with back-packing over the 
portages. 
With the advent of pack trains the mobility of the expeditions has 
been greatly increased, and they are no longer confined to the main- 
stream valleys. Horses, varying in weight from about 800 to 1,000 
pounds, are used, and from June to September they are self-supporting 
in most of the areas covered. When a party has started for the field 
in the winter, recourse has been had to dog teams, and this method 
was employed in the early part of the long journey across Alaska from 
the Yukon to the Arctic Ocean. 
The work along the coast has usually been done with whaleboats or 
small sailing vessels, but in the archipelago of southeastern Alaska 
gasoline launches have been used. 
The geologist who undertakes field work in Alaska is embarrassed 
by the fact that there are usually no base maps for his use. For this 
reason methods somewhat different from those ordinarily followed 
have been adopted. 
In connection with the regular instrumental surveys by the topog- 
rapher, a foot traverse of the route is made by the geologist, generally 
on the scale of 1 mile to the inch, with courses and altitudes determined 
by the compass and barometer, respectively, and distances estimated 
by pacing, or when traveling on the water b}^ timing. As the country 
is traversed the corresponding distances and bearings are platted in the 
