According to a government survey, of the nearly 400,000 acres of land in Riley County, about 20 percent is bottomlands, 80 percent uplands, 6 percent forest, and 95 percent prairie. The eastern and southern portions of the county have many bluffs and furnish the most picturesque scenery. The western and northern portions are for the most part, gently undulating; the rolling prairie being most beautiful in its waving swells and varied slopes. On the small creeks, the strips of bottom are quite narrow; the belts of alluvial lands along the Kansas, Big Blue, Fancy, Mill, and Wild Cat vary from one-half to four miles in width.


The composition of the soil is so varied in its chemical elements that nearly everything in the nature of grasses, grains, fruits and vegetables can be produced. The dark, easily-worked soil of the bottomlands is very productive. Its depth, ranging from two to fifteen feet comparatively, makes its fertility inexhaustible. Sand largely predominates over the clay element, and it very readily admits of drainage, so that it may be said there is next to nothing of stagnation in these bottomlands of large expanse. The uplands, less sandy than the bottoms, are fully as certain of bountiful crops, except in the occasional periods when burning droughts prevail. The almost total exemption of the crops on the high prairie from early and late frosts, and the salutary of the climate, causes the settlement of the uplands with great rapidity as compared with the early days. The bluffs, though presenting something of an appearance of barrenness, are exceedingly valuable for pastoral purposes. Supplied, as their sides are so often, with excellent springs of living water and the contiguous ravines, with their shady nooks, make most excellent ranges for cattle and sheep. Good brick-clay is found in the bottomlands and a beautiful magnesian limestone is distributed over the county; immense quarries being in the vicinity of Manhattan.

A large part of the Kansas River between the Big Blue and the Republican rivers is in Riley County, and on it are some of the garden lands of the State. During the territorial days of Kansas, steamboats came up the river to Manhattan and went as far as Junction City. Should the Mississippi, Missouri, and Kansas rivers, under the fostering care of the general government, receive bountiful appropriations, the bulky products of the soil are likely to be transported in floating barges down these improved navigable streams to the Gulf of Mexico. The Kaw, this noblest of Kansas rivers, is on the north line of Zeandale Township and runs very irregularly through Manhattan and forms considerable of the north and the northwestern boundary of Ashland Township, and the southwestern boundary of Ogden Township.


The Big Blue, forming the larger portion of the eastern boundary of the county, has fewer sharp bends than the Kaw, into which it flows at the east of Manhattan. It is so bountifully furnished with water power as to cause it to be designated the "Merrimac" of Kansas. It is dammed at Rocky Ford, some three miles above Manhattan. The fall is 10 feet and the dam 342 feet in length, and was built of heavy oak timbers bolted into the solid rock foundation. The Rocky Ford Mill is a 40 foot by 60 foot four-story structure, built in 1866. Its foundations are laid onto the solid rock and its walls, laid in cement, are four feet thick from the bottom of the river to the second floor. The river can be dammed below at Manhattan and above at Stockdale, Randolph, and Mariadahl. Swede Creek, Jackson, Grant and Manhattan are the townships bordering on the Big Blue. Fancy and Mill creeks, flowing southeast into the Kansas, water the center of the county. Madison, Timber and Three Mile creeks run west into the Republican and water the western portion; while south of the Kansas, McDowell, Deep and School creeks, traverse the southern part, the two latter being in Zeandale Township. The "Zeandale Bottoms" are regarded as the choice bottomlands of the county. Besides these, there are other small creeks, which, with their branches, give the county a most bountiful water supply.


There is quite a variety of timber, of which the most abundant are cottonwood, several kinds of oak and elm, black walnut, soft maple, hackberry, hickory, locust, ash, linden, sycamore, mulberry, box elder, and coffee bean. Of the cultivated groves, soft maple predominates, though black walnut, locust and cottonwood are quite common. Out on the high prairies, the groves of forest trees and the cultivated orchards which now bear in copious quantities some of the choicest of apples, pears and peaches, all attest to the assiduous care of the lover of horticulture, and the most excellent climate for various fruits.