Timber Creek and Rock Creek. Timber Creek drains a large level area, formed by the eroded upper portion of the Fort Riley limestone, in the north-central portion of the county. The gradient of Timber Creek is 12.9 feet per mile. The gradient of the Walnut River is only 2.3 ft. per mile from its point of entrance into the county to its mouth.

Fig. 1. Map of Cowley, Chautauqua and Elk counties, Kansas, showing the streams mentioned in the text

Grouse Creek, like the Walnut, has formed a valley of one to three miles in width, rimmed by prominent wooded bluffs. Those on the west side are capped by the Fort Riley limestone with the resistant Wreford and Crouse limestones forming lower escarpments. On the east side the Wreford and Crouse limestones provide the only escarpments along the stream above the Vinton community, except for occasional lower outcrops of Morrill limestone. Below Vinton the Fort Riley limestone again appears, capping the hills above the Wreford limestone. The headwaters of the western tributaries of Grouse Creek are generally in the Doyle shale formation; the eastern tributaries are in the Wreford limestone, Matfield shale, and Barnestone limestone formations. The gradient of Grouse Creek is 9 ft. per mile, of Silver Creek 14.6 ft. per mile, and of Crab Creek 14.4 ft. per mile.

The Big Caney River (Fig. 1), having a gradient of 15.4 ft. per mile in the area studied, drains an area with considerable geological and topographic variation. The main stream and its western tributaries originate in Permian formations, whereas the eastern tributaries originate in Pennsylvanian formations. Cedar Creek is exemplary of western tributaries of Big Caney. This creek arises in the Wreford limestone, as do several nearby tributaries of Grouse Creek. Although the Grouse tributaries descend through only part of the Council Grove group, Cedar Creek flows downward through the entire Grove, Admire, and Wabaunsee groups and part of the Shawnee Group (Moore, 1951). In only 15 miles, Cedar Creek traverses formations comprising more than 60 per cent of the entire exposed stratigraphic section in Cowley County. Bass (1929:16) states that reliefs of 350 feet within a mile are present in parts of this area.

Large terraces of limestone characterize the eastern flank of the Flint Hills, which the western tributaries of Big Caney drain. Most striking is the Foraker limestone. It characteristically consists of three massive members in Cowley County, the uppermost of which forms the prominent first crest of the Flint Hills. As the rapid-flowing western tributaries of Big Caney descend over these successive limestone members, large quantities of chert and limestone rubble are transported and deposited in stream beds of the system. In many places the streams of the Big Caney system flow over resistant limestone members, which form a bedrock bottom. The eastern tributaries of Big Caney drain, for the most part, formations of the Wabaunsee group of the Pennsylvanian. Most of these streams have lower gradients than those entering Big Caney from the west. The tributaries of Big Caney, along with length in miles and gradient in feet per mile, are as follows: Spring Creek, 7.1, 54.5; Union Creek, 6.3, 42.9; Otter Creek, 14.6, 27.4; Cedar Creek, 11.6, 31.0; Rock Creek, 15.9, 26.5; Wolf Creek, 9.3, 17.2; Turkey Creek, 8.5, 26.4; Grant Creek, 13.9, 23.4; and Sycamore Creek, 8.9, 27.0.

Spring Creek and Union Creek are short and have formed no extensive floodplain. The high gradients of these creeks are characteristic also of the upper portions of several other tributaries such as Cedar Creek and Otter Creek.

Middle Caney Creek (Fig. 1) has its source in the Wabaunsee and Shawnee groups of the Pennsylvanian but its watershed is dominated by the "Chautauqua Hills" of the Douglas Group. This area is described by Moore (1949:127) as "an upland formed by hard sandstone layers." The rough rounded hills supporting thick growths of oaks differ in appearance from both the Big Caney watershed on the west and the Verdigris River watershed on the east. The gradient of Middle Caney in Chautauqua County is 10.8 feet per mile. Its largest tributary, North Caney Creek, has a gradient of 15.5 feet per mile.

The Elk River Basin resembles the Big Caney River Basin topographically. Elk River has a gradient of 14.4 feet per mile.

PHYSICAL CHARACTERISTICS OF STREAMS

The stream channels derive their physical characteristics from the geological make-up of the area and from land-use. The Arkansas River typically has low banks; however, in a few places, as in the NE ¼ of Section 21, T. 33 S, R. 3 E, it cuts into limestone members to form steep rocky banks. The bottom is predominantly sand. In years of heavy rainfall the river is turbid, but during 1956, when it occupied only a small portion of its channel, it was clear each time observed. All streams surveyed were clear except after short periods of flooding in June, and except in some isolated pools where cattle had access to the water.

In the Walnut River, sand bottoms occur in the lower part of the stream but the sand is coarser than that of the Arkansas River. Upstream, gravel and rubble bottoms become more common. Steep rocky banks border most of the course of the Walnut. During 1956, stream-flow was confined to the center of the channel, remote from these rocky banks.

The rubble and bedrock bottoms found in most streams of the Flint Hills have been described. In the alluvial valleys of their lower courses mud bottoms are found. Gravel is present in some places but sand is absent. Banks are variable but often steep and wooded. Along east- or west-flowing streams the north bank characteristically is low and sloping whereas the south bank is high, rises abruptly, and in many places is continuous with wooded hills. The lower sections of Otter Creek, Cedar Creek, and Rock Creek fit this description (Bass, 1929:19) especially well, as does Elk River near Howard.

Streams in the Chautauqua Hills resemble those of the Flint Hills in physical characteristics, except that a larger admixture of sandstone occurs in the rubble.

CLIMATE

The climate of the area is characterized by those fluctuations of temperature, wind, and rainfall typical of the Great Plains. The mean annual temperature is 58 degrees; the mean July temperature is 81 degrees; the mean January temperature is approximately 34 degrees. The mean annual precipitation is 32.9 in Cowley County, 38.5 in Chautauqua County, and 35.1 in Elk County. Wind movement is great; Flora (1948:6) states that south-central Kansas ranks close to some of the windiest inland areas in the United States.

The area has been periodically subjected to droughts and floods. Such phenomena are of special interest to ichthyological workers in the area. At the time of this study drought conditions, which began in 1952, prevailed. Even in this period of drought, however, flooding occurred on Grouse Creek and water was high in Big Caney River after heavy local rains on the headwaters of these streams on June 22, 1956. Some of the lower tributaries of these same streams (such as Crab Creek and Cedar Creek) did not flow while the mainstreams were flooding. This illustrates the local nature of many of the summer rains in the area.

Table 1 indicates maximum, minimum, and average discharges in cubic feet per second at several stations in the area and on nearby streams. These figures were provided by the U. S. Geological Survey.

Table 1.—Cubic Feet Per