102 CONTRIBUTIONS TO THE GEOLOGY OF MAINE. [bull. 165. 
than 6 miles wide, but 30 miles farther north, in the valley of the 
Aroostook River, it widens to over 20 miles, and includes the prosper- 
ous townships of Fort Fairfield, Presque Isle, Mapleton, and part of 
Castle Hill, on the south side of the river, and Caribou, Woodland, 
and New Sweden on the north side. Farther up the Aroostook, about 
Ashland, is a limited amount of exceptionally fertile land. 
The amount of settled country, however, is but a small part of north- 
ern Maine. West and north of Ashland there is a stretch of unbroken 
forest extending nearly to the St. Lawrence River, visited only by 
hunters and lumbermen, who use the rivers and lakes as highways. 
Within the area described in this report there are some twenty town- 
ships with no sign of human habitation except the winter log roads 
and occasional lumber camps. The change from well-cultivated fields 
to an uninhabited expanse of forest, " burnt land," and swamp is sud- 
den and complete, as is well seen by ascending the highest points of 
the region. The pathless woods, with their soil thickly covered with 
products of forest decay, make the geologic investigation difficult, and 
render detailed mapping of extended sections impossible. 
PREVIOUS EXPLORATION. 
Geologic work in northern Maine has been carried on in the past by 
geologists employed by the State or by the Dominion of Canada. The 
first State survey was undertaken while yet the Aroostook lands 
belonged jointly to Maine and Massachusetts, and had in view the 
exploration of these lands preparatory to opening them to settlement. 
This first survey (now generally known as the Jackson survey) was 
instituted by an act of the State legislature passed on the 21st of 
March, 1836. 1 During the year 1836 a general topographic survey of 
the immediate vicinity of Houlton and of the St. John River from 
Woodstock to the mouth of the Madawaska was completed. In the 
following year Dr. Jackson, accompanied by Mr. Hodge, made the 
descent of the Aroostook River from La Pompique Stream to the St. 
John. The more important outcrops were located and briefly 
described, and the occurrence of iron ore in what is now Wade Plan- 
tation was dwelt upon at considerable length. 2 Exploration was not 
attempted except along the river. This report was written for the 
prospective settlers, and consequently the information as to trees, soils, 
and water supply is more complete and more valuable than the strictly 
geologic matter. The third and final annual report 3 of the Jackson 
1 Five thousand dollars was appropriated and Dr. Charles T. Jackson was placed in charge. Asso- 
ciated with him in the first year's work were Dr. T. Purrington, as agent on the part of Maine, and 
James T. Hodge, who represented Massachusetts. The survey was continued for three years, with 
different assistants and smaller appropriations each year. 
2 Second Ann. Rept. on the Geology of the Public Lands belonging to the two States of Maine and 
Massachusetts, Augusta, Maine, 1838. 
3 Augusta, 1839. 
