BIG SPRING PRAIRIE. 25 
slope of West Ridge and the locality just across the 
Hocking Valley R. R., where the Niagara limestone 
lies within a foot or two of the surface. 
The northern portion of the prairie from Spring- 
ville westward was drained by the outlet mentioned in 
the treaty, which was made with the Wyandot Indians 
in 1818. -The Blanchard River is about five or six 
miles west from the western boundary of the Indian 
Reservation. In the treaty this would scarcely be re- 
ferred to as the head-waters of Blanchard’s Fork, so 
there must have been a tributary of this name _ suffi- 
ciently open to warrant mention. According to the 
testimony of the older settlers, there was no well-defined 
open stream in 1840. Blanchard’s Fork must have 
gradually become clogged up by an encroaching growth 
of cattails, sedges, grasses, water-plants, and arrow- 
leafs: thus producing the sluggish outlet frequently 
mentioned by the old settlers. 
The southwestern extremity of prairie near Vanlue 
had a broad sluggish drainage to the southwest along 
two shallow valleys. 
Whether all of these outlets existed when the area 
was a lake, or originated after it had developed to the 
marsh type, it is difficult to determine: but, most prob- 
ably the outlet was the only one, the others originating 
after the surface of marsh was built up higher than the 
original level of the lake. 
This would seem to be a natural consequence, for 
there are several areas of limited extent in various por- 
tions of the prairie which would corroborate this view. 
These areas are elevated several feet above the sur- 
rounding level, although they consist of muck, of as 
great or greater depth than the adjoining portions. 
This greater elevation of a portion of a marsh is a com- 
mon formation in a Sphagnum swamp. The writer 
has never been able to find any Sphagnum whatever 
on this area, or any traces of it in the muck, although 
