The Great Terrace of the Cohimbia. — Russell. 367 
where the Methow comes in there is a bold rock}' promontory, 
on the plateau-like surface of which there are a few crags ris- 
ing above the level of the great terrace. This rock mass is 
separated from the mountains to the east by a coulee through 
which the Columbia or a part of its waters once flowed. The 
bottom of the coulee is below the level of the great terrace." 
The explanation of the origin of the coulee which presented 
itself to me, from the facts as I saw them, is, that the river 
when its channel was occupied from side to side by the gravel 
deposit now represented by the great terrace, was greatly ex- 
panded, being a broad, swift stream, and that a portion of its 
current followed the now abandoned coulee, leaving the crags 
on the surface of the mesa at the summit of the promontory, 
as islands. Later, when the Columbia re-excavated its chan- 
nel, the branching passage in solid rock w^as abandoned. The 
river did not make the coulee, but simply modified its bottom 
to some extent. The origin of the coulee need not be dis- 
cussed at this time but the fact that it is older than the great 
terrace is beyond doubt. This explanation meets all of the 
conditions as I saw them, and is in harmony with the histories 
of other coulees, similar to the one described above, and be- 
sides is independent of the Methow glacier, which according 
to my observation did not come within at least forty miles 
of the region under discussion. 
Antwiiie's Coulee: On the west side of the Columbia 
valley and south of the mouth of the Methow, there is a deep, 
narrow channel, similar in character to the one referred to 
above, but of much larger size, known as Antwine's coulee. 
As correctly stated by Dawson, Antwine's coulee connects the 
Methow valley at a locality about four miles above its mouth 
with the' Columbia valley, some ten miles to the south. This 
deep, narrow defile is described by the author cited above as 
a glaciated channel, "which the ice has hollowed out between 
some sturdy outlying spur and its parent mountain." 
I traversed the entire length of Antwine's coulee last 
September, but failed to find any evidence to suggest that it 
had once been occupied by a glacier. The narrow, steep 
sided trench is crossed from side to side by alluvial cones, and 
talus slopes, between which there are several undrained basins, 
three of which hold lakelets. The coulee is also obstructed bv 
