collier.] CHARACTER AND VALUE OF THE COALS. 65 
this coal field have not been determined, but there are probably 
between 50 and 100 square miles of coal land contiguous to this mine, 
the greater part of which lies some distance from the Yukon. 
In American territory, on Washington Creek, about 12 miles from 
the Yukon, there is another large held, which will probably yield a con- 
siderable supply. This coal is a lignite, and is, so far as the analyses 
show, of slightly lower grade than that at Cliff Creek. 
In the Rampart province the coal field of the Drew mine is the only 
one which has immediate value, and it is of very limited extent, the 
area of coal-bearing rocks probably not exceeding 1 square miles. The 
coal is a lignite, containing higher percentages of water and ash than 
the standard coals of the Circle province. 
In the Nulato province coal has been exploited at a number of locali- 
ties in the coal-bearing rocks which extend along the Yukon for 200 
miles. The coal beds are usually rather thin, none of them measuring 
over 1 feet, and some of the seams are so crushed by shearing faults of 
the inclosing strata that systematic mining is difficult. At Williams 
mine, 90 miles below Nulato, in this belt, the coal bed is regular and 
holds a uniform thickness as far as development has gone. The con- 
ditions are favorable for producing a large amount of coal. With 
proper development the mine can probably supply all the coal that 
will be required on this part of the Yukon for many years. The coal 
here is bituminous, having a fuel ratio of from 1.2 to 1.5 and a water 
content below 7.5 per cent. 
Coal of a better grade is found at the Pickart mine and at the Blatch- 
ford mine, also in this province, but the beds are faulted and the con- 
ditions for producing coal are not favorable. At the latter mine the 
coal is by proximate analysis the best found by the writer on Yukon 
River, having a fuel ratio of 3.3, water content below 2 per cent, and 
ash below 3 per cent. 
Many steamboat men prefer the lignitic coal from Cliff Creek mine 
to the coals from the vicinity of Nulato. This is probably to be 
accounted for in part by the character of the grates on which it is 
burned, since the Cliff Creek coal burns more freely and produces heat 
more quickly than do the coals of the lower river. 
The lignites of the Circle and Rampart provinces are contained in 
sandstones of Eocene age, correlated with the Kenai series. The 
bituminous (Nation River) coal of the Circle province is probably of 
Permian age, while the bituminous coals of the Nulato province are 
contained in a series of sandstones in part Upper Cretaceous and in 
part Eocene in age, which has not yet been separated on stratigraphic 
or lithologic grounds. The Pickart and Blatchford coals are Upper 
Cretaceous, while the Williams coal is Eocene, in age. 
Bull. 218—03 5 
