Bottomlands Restoration


Bottomlands or river bottoms are found in the floodplains of the Missouri River above maximum lake level. They occur only on the west end of the refuge. There are about 16 river bottoms covering a total area of approximately 5,000 to 7,000 acres.


A diverse mixture of native trees, shrubs, forbs, and grasses characterizes the river bottom plant community. Trees and shrubs present are green ash, boxelder, redosier dogwood, silver buffaloberry, golden currant, western snowberry, Woods’ rose, chokecherry, sumac, plains cottonwood, sandbar willow, peachleaf willow, and a couple of other willow species. Native forbs present include Maximilian sunflower and American licorice. Native grasses present are bluebunch wheatgrass, green needlegrass, prairie cordgrass, basin wildrye, western wheatgrass and reed canarygrass.

Historically, many of the river bottoms on the refuge were cleared. Native plant communities were plowed, and nonnative agricultural crops were planted because these were the most productive areas. Farming the river bottoms occurred for decades, but the last homesteader on the refuge stopped farming in 1983–84, and the last two bottoms to be planted to crops have not been farmed since 1985–86. Even though the farming has stopped, the threats to the river bottoms have not. Native plant communities that once existed on these bottoms have been unable to reestablish themselves and the plant communities left existing on the river bottoms have now mostly been invaded by Russian knapweed, leafy spurge, smooth brome, and quackgrass, which have very little value to wildlife.

                bottomland tractor medium 


In 2004 CMR began restoring 160-acre Irish Bottom and has also begun restoration on Knox Bottom (160 acres) and Kendall Bottom (175 acres). The most significant threat to river bottom health is from exotic species which have been increasing in many areas largely because of two reasons: (1) lack of seed source to establish native plants that would compete with or outcompete the invasive weeds; and (2) extensive browsing on sentinel plants that are established. Establishing and maintaining healthy native plant communities is an important way to slow or prevent reestablishment of weeds after they have been treated mechanically, chemically or with biological control. The Service is currently consulting with experts from NRCS and State agencies to determine the best methods to restore these bottomlands back to healthy native plant communities. Ultimately, restoration of the river bottoms will consist of a healthy native plant community including those that would have occurred on the river bottoms 150 years ago.

Timeline of Restoration on CMR National Wildlife Refuge 

Restoration is time and labor intensive and involves burning, tilling, spraying, seeding and mowing in a process that takes several years.


bottomland burn

Irish Bottom 160 acres
2004 Prescribe burned in the fall
2005 to 2008 Sprayed with Roundup and tilled multiple times
2008 Seeded with native grass/forb mix in the fall (grass: basin wildrye, western wheatgrass, slender wheatgrass, green needlegrass; forbs: maximillian sunflower, purple prairie clover, white prairie clover)
2011 Missouri River flooded during spring

Knox Bottom 160 acres
2009 Sprayed with Milestone herbicide to control Russian knapweed
2010 Sprayed with glyphosate, prescribe burned in August, sprayed a second time and seeded native mix in the fall with no-till drill
2011 Missouri River flooded during the spring which helped germination

bottomland flood 


Kendall Bottom 175 acres
2012 Prescribe burn in August
2013 and beyond Spray with Milestone Herbicide and continue spraying until Russian knapweed is controlled, then plant native seed mix


Given adequate moisture, the rich soils of the bottomlands produce a thriving vegetation community. Russian knapweed is a continuing threat but it is hoped that the chosen seed mix will be able to outcompete this noxious weed.  

bottomland success