THE NORTHERN PACIFIC ROUTE. 85 
The train is now approaching the place of origin of this material. 
The gray sandstone of the Lance forms most of the slopes at milepost 
50, just beyond Merrill, and about 300 feet above the river the hills 
have a brownish appearance which indicates that some other forma- 
tion makes their upper slopes. After crossing the river the same rela- 
tions may be observed, except that as the train moves westward the 
brown Lebo shale can be seen at lower and lower levels, owing to the 
slight westward dip of the rocks. 
At Reed Point the white beds of the Lance extend up the slopes 
only 100 to 150 feet, and above that all the rocks are brown. The 
Lance probably goes under river level near milepost 
Reed Point. 60, and beyond that point the hillsides are much 
erp ecg smoother and the general tone of the rocks is brown, 
indicating that the Lebo shale forms the. hills at 
least for a height of 800 or 1,000 feet. 
About three-fourths of a mile beyond milepost 63 a large dike, 
visible on the right (north), cuts directly through the bedded rocks 
in a direction nearly parallel with the railway. The dike is composed 
of a dark igneous rock which was injected in a melted condition into 
an extensive crack in the bedded rocks. It stands up like a wall, and 
where it cuts across a bed of light-colored sandstone it is easily 
recognized, 
As the train rounds the curve at milepost 66, the traveler looking 
forward and to the right can get his first good view of the Crazy 
so thoroughly washed and sorted by water that it is evenly bedded 
like ordinary shale and friable sandstone, but near the mountains and 
the source of supply this material is coarser and some of it has the ap- 
pearance of being only a little modified by water after it was blown out 
of some old volcanic vent in the vicinity. Such material, known as 
volcanic agglomerate, is composed of fragments of lava ranging from 
minute pieces to blocks 4 feet in diameter. The agglomerate beds 
have in general a warm gray tint, and a mass of such material gave 
the name of Greycliff to a siding that was formerly located under the 
cliff but now has been moved 3 miles to the west. The cliff is fully 
100 feet high, but the base of the agglomerate is not exposed and 
hence its full thickness may greatly exceed that amount. As it is 
reported to be 2,000 feet thick a few miles to the southwest, itseems _ 
reasonably certain that the old volcano which furnished the material 
was located in that direction, but no trace of it has been discovered. 
