Wetlands of the Central Plains
Kansas and Missouri

Wetland Environments
James S. Aber

Table of Contents
Introduction Squaw Creek NWR
Flint Hills NWR Quivira NWR
Related sites References


Wetlands in Kansas and Missouri share many common traits with those of the northern plains region, but there are some notable differences beginning with climate. In the central plains, summers are long and hot; winters are relatively short and cool, although brief cold spells may occur. A pronounced moisture gradient exists from east to west. Generally all of Missouri and the eastern half of Kansas have a water surplus, as evidenced by many large rivers that drain the region. However, western Kansas experiences a water deficit most years; there are no large rivers and few perennial streams.

In contrast to the northern plains, which have countless natural lakes, ponds and undrained depressions, the central plains have few natural lakes. This difference derives from the history of glaciation during the ice age. Glaciation of the northern plains ended only 12,000 to 14,000 years ago, and a rich variety of poorly drained landforms is well preserved. In contrast, northeastern Kansas and northern Missouri were glaciated more than half a million years ago (Aber 1991). Most glacial features have since been destroyed by prolonged weathering, erosion, or infilling with sediment. The maximum limit of glaciation corresponds approximately with the Blue/Kansas river valleys in northeastern Kansas and the Missouri River valley across northern Missouri. Regions to the south were never glaciated.

Wetlands of the central plains occupy a key position along the central flyway for migrating shorebirds and waterfowl. These sites provide stopping places where birds feed and rest before continuing their semiannual treks to the north or south. In order to demonstrate the variety of wetland environments, three National Wildlife Refuges (NWR) are illustrated below. The U.S. Fish and Wildlife Service, which operates the NWR system, has become the premier national agency for preservation, restoration, and maintenance of wetlands devoted to wildlife habitat. The NWR system celebrated its centennial in 2004.

Squaw Creek NWR, Missouri

Squaw Creek NWR is located on the eastern side of the Missouri River valley next to Mound City, in northwestern Missouri, approximately 75 miles northwest of Kansas City. Founded in 1935, the refuge comprises 7350 acres mainly in the bottomland and partly along the eastern valley bluff--see
refuge map. The bottomland includes extensive man-made marshes, reclaimed from former cropland, and the bluff is wooded loess hills. Loess is thick, wind-blown silt and clay derived from the adjacent valley bottom during the ice age. The marshes are managed for shorebird and waterfowl habitat. Bald eagles nest here, and more than 300,000 snow geese and 100,000 ducks stop over during their seasonal migrations. All together the refuge hosts more than 300 species of birds, 30 mammals, and 35 reptiles and amphibians.

Satellite image of Mound City-Rulo vicinity, Missouri, Nebraska and Kansas. Note the remarkable expansion of the Missouri River bottomland between Rulo and Mound City. Squaw Creek NWR is located on the eastern side of the extra-wide valley. Landsat TM 257 composite; image date 2 July 1997.

The Missouri valley is exceptionally wide at Rulo-Mound City, approximately 11 miles (18 km) across. In contrast, the Missouri valley at Kansas City is only about 2 miles (3 km) wide. The difference stems from geologic conditions. The Missouri River at Mound City crosses a buried glacial valley that is filled with loose sediments--sand, gravel and mud, which are easily eroded as the river meanders back and forth. At Kansas City, however, the Missouri River cuts through thick limestone beds that are resistant to erosion and have maintained a narrow valley.

The following airphotos were taken from a small helium blimp in June 2003. Special thanks to Sara Acosta for making arrangements to conduct aerial photography at Squaw Creek NWR.

View westward across the Missouri River valley. Mallard Marsh to lower right; Pintail Pool at lower left. Notice the airboat in Pintail Pool.
View toward the northwest over Mallard Marsh. The green carpet is arrowhead (Sagittaria brevirostra), an emergent wetland plant. Tail fin of the blimp is visible at top of picture.
Color-infrared photograph, in which active vegetation appears in pink and red colors. View toward northwest over Mallard Marsh. The marsh displays a homogeneous, smooth cover of arrowhead vegetation.
Color-infrared photograph. View toward southeast over Pintail Pool. Note the mosaic of vegetation types and open water.
Low-oblique view of Mallard Marsh. Vegetation is a carpetlike cover of arrowhead. The trees (on drier soil) are often used by eagles for nesting.

Flint Hills NWR, Kansas

This refuge is located immediately upstream from John Redmond Reservoir, a flood-control dam and reservoir operated by the U.S. Army Corps of Engineers--see refuge map. The refuge includes much of the "floodpool" bottomland that may be inundated during high water.

Superwide-angle view over the Neosho River in the foreground and John Redmond Lake in the background. The floodplain forest is part of the national wildlife refuge. Photo by B. Zabriskie, Oct. 2008.

A small portion of the Neosho River valley floodplain is set aside for an experiment in vegetation growth, which has been monitored by ESU students. Several small "potholes" were excavated with a bulldozer in 1998, and the site has been allowed to experience a natural succession of wetland vegetation.

Map of the Hartford vicinity showing the pothole study site and location for the Flint Hills National Wildlife Refuge (FHNWR). The blue shading indicates the maximum flood level for John Redmond Reservoir, which is downstream on the Neosho River. Adapted from the Hartford, KS 7-minute topographic quadrangle, U.S. Geological Survey (1970).

The pothole study site is a triangular-shaped area. County roads mark the southern and western boundaries, and the northeastern boundary is an old railroad grade (see map above) marked by a line of trees. The area of the study site is approximately 6.8 acres (2.7 hectares). The following kite and balloon aerial photographs were taken during the spring of 2001 to show the progression of vegetation growth and water conditions.

April airphotos: Preliminary kite aerial photographs were collected on April 25, 2001, early in the growing season. The site was relatively wet following early spring rains.

View toward southeast with the city of Hartford in the background. Various agricultural landuse is present in the foreground on the floodplain and low terraces of the Neosho River valley. Note lush green hay fields in middle distance.
Low-oblique view of northwestern portion of study site. Road is the western boundary of the study site. Potholes here hold water well; notice old bulldozer tracks visible between potholes.
Low-oblique view of eastern portion of study site with kite flyers at top center of scene. A water-fill pothole is present at bottom-center of scene; other potholes in this portion of the study site are dry and display minimal growth of wetland vegetation. The two dark spots to left are shadows of two large rokkaku kites used to lift the camera rig in a light breeze.

May airphotos: Airphotos were collected on May 26, 2001. During the month since the April images were acquired, little precipitation fell and the soil was noticably drier. No potholes had standing water.

Low-oblique view of the western portion of the study site. The car sits on the N-S road that marks the western boundary of the site. Blunt spike rush (Eleocharis obtusa), a typical wetland indicator, forms the dark green borders around potholes, which have no standing water at this time. Some larger potholes had wet soil.
Low-oblique view of the eastern portion of the study site. The road is the southern boundary of the site. Potholes on eastern side (lower 2/3s of view) are completely dry and display no wetland vegetation.

The site contains about 25 potholes in various sizes, shapes and orientations. Some of these are well marked, others are more subtle. Additional poorly expressed potholes may be present. As noted above, potholes in the center and toward the west tend to hold water and have blunt spike rush; potholes toward the east are relatively dry and have little or no wetland vegetation. The site includes two soil types (Neill 1981).

Chase silty clay loam covers most of the study site, and Ivan silt loam occupies the eastern corner of the site. This suggests a decrease in clay content and increase in soil permeability toward the eastern end of the site, which may explain the variations in pothole characteristics.

June airphotos: A third set of airphotos were acquired on June 15, 2001, following two weeks of heavy rain. The site was covered with lush vegetation and most potholes contained standing water.

Near-vertical view, south-central portion of study area. Road to upper right is southern boundary of the study site. Aerial targets are 5x5-foot squares.
Near-vertical view, north-central portion of study area; north toward left. Notice the people standing next to a target; they were collecting GPS readings on the target position.
Color-infrared view toward the southeast. Line of trees on left marks the old railroad grade. Notice bright red-pink color of most vegetation. Potholes are relatively dark; aerial markers can be seen in the southeastern portion of the study area.
Color-infrared view toward the southwest. Potholes appear relatively dark compared to surrounding vegetation, because of standing water, wet soil, and sparse vegetation in potholes. Blunt spike rush on pothole margins has a dark reddish-brown color in contrast to red-pink of other vegetation.
Ground view of study site, as seen from the southwestern corner looking toward the east. Large pothole in southwest corner of the study site appears in the left center of view (other side of road). This vantage provides little information about the potholes and wetland vegetation patterns.

Quivira NWR, Kansas

Quivira National Wildlife Refuge is a salty wetland complex in south-central Kansas near the city of Stafford. The wetland consists of two large pools--Little Salt Marsh and Big Salt Marsh, along with numerous smaller marshes, meadows, and sloughs that total more than 7000 acres (2800 hectares). Established in 1955, the refuge is located along the Great Plains migration route for waterfowl and shorebirds. Tens of thousands of ducks, geese, cranes, pelicans and other birds utilize the marshes during their spring and autumn migrations northward and southward. The refuge is managed to maintain and enhance habitat for these migrating birds and other wildlife of the region. Students will visit Quivira NWR as part of our long field trip toward the end of the semester.

Shallow marshes and mudflats are prime habitat for migrating shorebirds and waterfowl, so water supply and control are critical concerns for the refuge. Water inflow comes from Rattlesnake Creek, a saline stream that enters Little Salt Marsh from the southwest and exits the refuge to the northeast. Twenty-one miles (34 km) of canals along with many levees and other drainage-control structures are used to divert, store, and distribute water throughout the refuge. The salt is derived from subsurface bedrock that contains salt layers. Ground water dissolves the salt and transports it toward the surface, where it emerges in saline springs and streams.

As the water moves through the marshes, evaporation leads to increased salinity of seawater character. Prairie cordgrass (Spartina pectinata), also known as sloughgrass, tolerates high salinity levels and thrives at Quivira NWR. The refuge includes an oil field with both active wells and former well sites. Operation of the oil field has little impact on the wetland environment nowadays.

Little Salt Marsh
Aerial view toward the northwest showing the levee and water control structures on the northern side of Little Salt Marsh. Outflow of Rattlesnake Creek is to upper right. Photo JSA, May 2003.
Ground view of the water control structure for outflow to Rattlesnake Creek from Little Salt Marsh. Photo JSA, May 2003.
View toward the southeast, immediately east of Little Salt Marsh. Wet meadows have a lush green color following spring burning in this portion of the refuge. Photo JSA, May 2003.
View toward the northeast over a large, meandering, water-filled slough. Photo JSA, May 2003.
Northward view over a mosaic of pools, potholes and hummocks of the wetland complex. Photo JSA, May 2003.

Big Salt Marsh
Aerial view toward the southeast over Big Salt Marsh with high water. The public wildlife-viewing road follows the dike across the scene. The square structure left of center is the remains of a former oil well. Photo JSA, May 2008.
Ground view of prairie cordgrass (Spartina pectinata) growing on the margin of Big Salt Marsh with oil wells in the background. Photo JSA, May 2003.
Midland smooth softshell (Apalone mutica mutica) turtle seen on the road at Big Salt Marsh. Softshells are usually aquatic. They are strong swimmers and fast runners. Softshells are carnivores eating various invertebrates, fish, and amphibians (Sievert and Sievert 2006). Photo JSA, May 2008.

Related NWR sites


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© Notice: Wetland Environments is presented for the use and benefit of students enrolled at Emporia State University. Any other use of text, imagery or curriculum materials is prohibited without permission of the instructor, J.S. Aber (2016).