ransome.] LODES OF POUGHKEEPSIE GULCH. 191 
was producing copper and silver ore as early as 1878. The lode, as 
revealed on the surface, is a sheeted zone in an amygdaloidal andes- 
ite. The fissures comprising this zone contain very little quartz, and 
the only ore seen on the surface consisted of the carbonates of copper 
disseminated through the amygdaloid. Good ore, consisting of tetra- 
hedrite with some "brittle silver," is said to have been taken from a 
shaft sunk on the lode. A crosscut tunnel GOO to 700 feet in length 
was run lower down in the gulch, but did not reach paying ore. The 
dump of this tunnel shows some chalcopyrite deposited in a breccia 
zone in the nndesite. The average strike of the Dolly Varden lode is 
nearly north and south, with an easterly dip. 
Other prospects. — On Copper Mountain the John J. Crooke, Big 
Horn, and other prospects have been worked intermittently for many 
years and have produced some ore, chiefly argentiferous bornite and 
chalcocite (stromeyerite), with a little galena and some native silver, 
in a gangue often containing considerable calcite. The strike of these 
lodes is usually a little east of north, with steep easterly dips. The 
country rock is andesite. 
Other prospects have been opened in a small way in the gulches and 
basins south of Henson Creek. These are chiefly galena ores, carry- 
ing some silver and a little gold, in andesite country rock. 
LODES OF POUGHKEEPSIE GULCH. 
General. — There is no reason, other than that of convenience, for 
separating these veins as a whole from those about Mineral Point, of 
which they are in many cases the direct continuation. Formerly the 
scene of busy activit} T , the gulch, with the exception of two or three 
prospectors, was deserted when visited in 1899. The first location was 
the Poughkeepsie claim, staked by K, J . McNutt in 1874. In 1879 min- 
ing was actively proceeding in several claims. A road was built from 
Cement Creek to the head of the gulch, and lixiviation works were 
erected at Gladstone to treat the ore. Since 1890, however, the only 
work done has been desultory prospecting on a small scale. 
In general the longer fissures have trends vaiying from N. 30° E. 
to N. 50° E., with southeasterly dips. But they are sometimes curved 
and irregular, and near Lake Corao occurs the most remarkable group 
of large, closely spaced lodes to be found in the quadrangle. An 
observer standing on the north side of the lake may count at least five 
prominent veins running down the steep slopes to the south and west 
and passing beneath the deep blue water of the tarn. At the point 
now occupied by the latter the fissures were deflected sharply east- 
ward, and from the eastern side of the lake four prominent lodes and 
many smaller ones converge at a point on the ridge separating the 
head of Poughkeepsie from California Gulch. In addition to these, 
numerous other lodes come in through the saddle connecting with 
Ross Basin and converge toward the same point on the ridge. The 
