12 
The third division comprises all the land watered by the Bio- Thomp- 
son between the point where it Issues from the mountains and its junc- 
tion with the South Platte River. 
In order to confine this discussion within the narrowest possible 
limits, except in so far as the other divisions may affect the third, that 
division, by far the most important and the most interesting, alone 
will he considered. 
To one standing on the outer range of foothills near the mouth of 
the canyon and looking east, the entire valley of the Big Thompson is 
visible. To the north, extending eastward, is the ridge between the 
(ache la Poudrc and Big Thompson rivers, some 10 miles away at the 
westerly end. and gradually approaching the river on its eastern trend. 
The ground sloping gently to the river appears somewhat rolling. 
To the south a similar ridge marks the boundary between the Little 
and Big Thompson rivers. Less rolling, the country here presents a 
smooth, even slope to the river. 
The elevation and the fall of the river are such that the higher 
ditches skirting the foothills soon reach the crests of those ridges and 
extend down them to the limit of their supply of water for the lower- 
lying land, but supplying water to lands on both the Cache la Poudre 
and Little Thompson slopes. 
WATEE SUPPLY. 
Under this head will be found the data collected for a number of 
years on the subject of precipitation and run-off. - 
The gauging station on the Big Thompson River was established in 
1883 by the late E. S. Nettleton. then State engineer of Colorado, and 
was located "about 200 yards above the head of the upper ditch. 12 
miles from Loveland." This station being found unsatisfactory, was 
abandoned, and in 1887 another was established about 10 miles west of 
Loveland and was maintained until 1892. In 1893 and 1891 no read- 
ings were taken on the river. On May 9. 1895, a third station was 
established some 9 miles west of Loveland. Being below both the 
Handy and Home Supply ditches, a record of both of these, entailing 
considerable extra labor, was necessary. On this account the station 
was moved to a point above the head of the Home Supply Ditch April 
1, 1899. This station, located about 3 miles south of the post-office at 
Arkins, at a point where the wagon bridge crosses the stream, though 
below the Handy Ditch, is quite satisfactory. The gauge rod is a verti- 
cal 2-by-4 fastened on the downstream side of the south abutment of 
the bridge. 
The channel, though quite rough and full of bowlders, is permanent, 
and the results obtained are reliable. The entire record for the river 
at the several stations is given in the accompanying table: 
