Drift near Seattle, Tacoina and Olyiiipla. — Uphani. 217, 
railway that extends from Tcnino east and northeast to Taco- 
ina. From Mr. Henry's manuscript map of the county these 
prairies are mapped on plate xiii, accompanying this paper. 
Grand Mound prairie Ijeginning three miles north of the 
railway station of Grand Mound, and reaching thence seven 
miles east to where it is crossed hy the railway hetween Tenino 
and Bucoda, has an immense numher of gravel mounds and 
short ridges, from 2 or 3 feet to 10 or 15 feet in hight, often 
very irregularly grouped, with hollows entirely inclosed, like 
ordinary kames. 
Tenalquot prairie, partly a grassed area, and partly covered 
with hushes and scattered trees, 6 to 10 miles northeast of 
Tenino, has many mounds, hut reticulated kames there pre- 
dominate, as descrihed hy Henry, rising to higlits of 25 to 
50 feet, with many inclosed hollows, 10 to 20 feet deep. The 
southeast corner of this prairie is crossed by the railway at 
Rainier station, about nine miles east-northeast of Tenino. 
\"ery fine views of Mt. Rainier, 40 miles east, are seen from 
this knolly and ridged open tract. 
Four to six miles northeast of Rainier station, the railway 
crosses Yelm prairie, on which is Yelm station, near its cen- 
ter. Mr. Henry describes the west half of this prairie as 
having a contour of low ridges and mounds, while its east half 
is nearly flat but has on its southeastern edge many boulders, 
this being the only locality of their occurrence known to him in 
Thurston county. 
Mapping these five "mound prairies"" in a curved belt of the 
marginal drift, six to eight miles wide, I trace its probable 
continuation east and northeast in Pierce county by the occur- 
rence of numerous lakes inclosed by the same gravel deposits, 
the largest being Kipowsin lake, about three miles long, trend- 
ing east and northeast. The belt at the northeastern Ihnit of 
my map (Plate XHI) comprises township 19 north, range 6 
east, where Willis noted plentiful drift gravel ridges, knolls, 
and hollows, in the vicinity of the many lignite coal mines of 
that township, which is in an entirely wooded region. 
Similarly these low kames or marginal mounds and ridges 
of the Puget sound ice lobe are undoubtedly traceable through 
all the wooded parts of this belt, not less than on its prairie 
tracts, where their surprising abundance has been especially ob- 
