shore IJtx'-s of Ancient Glavial Lalcx. — Todd. 301 
miles west of the Missouri, is aliout 2.40(1 feet al)ove the sea. 
Along its northern slope is a peculiar fiat-topped, V)utte-like ridge 
running east and west for 15-20 miles, its top being nearh- hori- 
zontal and aV)out 50 feet lower than the summit of Fox ridge. 
This was determined not only by several barometic readings, 
but by distant views from lioth north and south. The ridge is 
well covered with granite boulders, and drift 2-5 feet thick, but 
strange to say. no northern drift was found south of the ridge, 
except where its presence could be accounted for by recent trans- 
portation. The land just south of the ridge is frequently 50 feet 
lower than its top. This ridge is not strictly continuous. There 
is a wide gap. particularly, where it is crossed by the Virgin creek. 
The margin of the drift I had not time to trace fully, but was 
informed by Mr. Kiggs, who knows the region well, that it crosses 
the Moreau 25-HO miles west of its mouth and runs northward at 
al>out the same distance from the Missouri for an indefinite dis- 
tance. Inside this margin the land nowhere rises higher than the 
margin, and it is here and there sprinkled with northern bould- 
ers, often in patches, especialh' on the higher levels. The divide 
between the Moreau and Grand rivers has an altitude of about 
2.:}<l0 feet. Most of the surface is of Cretaceous clays, and is 
much eroded, the alternating layers of hard and soft material, 
producing an interesting topography, studded here and there with 
high, flat-topped buttes. 
The course of the marginal ridge south of the Moreau is in 
line with some high clay buttes on the east side of the Missouri, 
just al»ove the mouth of the Little Che^'enne, which are known as 
Welland .V)uttes. They are strewn with a thin layer of boulders, 
and are the west end of a high divide separating the Little Chej'- 
enne and Swan Lake creek. Crossing this divide is a well pre- 
served ancient channel, more than 400 feet above the ^Missouri, 
and there are traces of an old terrace along the Missouri, near the 
Welland l>uttes, at about the same level. 
Putting these things together, we come with some confidence to 
this conclusion: Fox ridge, with its eastern extension, the Wel- 
land buttes and the high land southwest of Howdle and west of 
Faulkton, once formed the divide between the ('he3'enne and 
Moreau rivers, when they flowed through to the James rivei- val- 
ley. When the great ice sheet came down the latter valley dur- 
ing the glacial period, and occupied the outermost terminal mo- 
