128 GUIDEBOOK OF THE WESTERN UNITED STATES. 
The rocks north of Garrison are mostly of Cretaceous age and cor- 
respond to the Colorado shale, which is exposed in the bluff south of 
Billings. At Billings the formation consists of dark shale containing 
many marine fossils, but about Garrison it is composed largely of 
sandstone, conglomerate, and tuff, and no marine fossils have been 
found in it. The kind of material composing the formation and the 
character of the fossils indicate shore conditions and fresh or brackish 
water, instead of the salt water that prevailed farther east. North of 
Garrison the Cretaceous rocks are cut by igneous rocks that have 
been forced up through them in great masses and in narrow dikes. 
The most prominent igneous mass that can be seen from the train is 
one that crosses the track at milepost 56. This rock has been quar- 
ried for material with which to riprap the slopes of the roadbed 
where it is washed by the stream. At milepost 57 there is a high, 
rocky wall on the left composed of sandstone in which there is the 
standing stump of a tree. It is now silicified but remains as a mute 
record of a time, long ago, when this country, now so barren of tim- 
ber, was covered with trees several feet in diameter. About halfway 
between mileposts 57 and 58 is the mouth of Gold Creek, the creek 
upon which gold was first discovered in Montana.! The placers 
are at Pioneer, 5 miles up the creek, and it is reported that at least 
$12,000,000 has been taken from them. They are still producing ina 
small way. Cretaceous rocks form the surface here, but they are 
generally soft and give rise to low hills and gently rounded slopes. 
At the station of Gold Creek the valley floor merges into the 
rolling upland that stretches far northeastward to the foot of the 
Garnet Range, which is composed of Paleozoic lime- 
stones and quartzites. At milepost 61 the valley 
widens, and 2 miles farther west the harder rocks 
disappear and the valley floor and the slopes are 
composed solely of the lake beds, which mantle all the 
older formations. The lake beds continue to milepost 68, where the 
Cretaceous rock is again visible on the north. 
Litas 
Population 730.8 
St. Paul 1,187 miles. 
4 J it 4 » Oe! _. But 
ered in Montana i in 1852 by a half-breed 
named Frangois, but better known to his 
associates as Benetsee. his return 
from the gold fields of California Benetsee 
began pr ospecting on on what is now known 
as Gold Creek, in Powell County. He 
, but did not obtain 
with the Indians, visited Gold Creek and 
found more gold than Benetsee had been 
able to obtain, but not enough to induce 
them to remain 
Desultory pr cspecting was done in the 
years following the visit of this party, but 
without any definite result until 1862, 
placers of Alder Gulch, at Virginia City 
(1863), and Last Chance Gulch, at Helena 
(1864), were discovered 
overshadowed the deposit on Gold Creek 
that it was almost forgotten. 
ed, and these so far 
