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Yellow Flag Iris (YFI) (Iris pseudacorus) is a non-native, invasive plant that is causing substantial changes to the ecology of wetland and riparian areas. Due to the limited options for invasive plant management in these areas, we explored a non-chemical approach. During a previous study on YFI, we noted the development of footpaths around our study plots. As a result, we decided to conduct both field and greenhouse studies to explore the effects of trampling on YFI and determine if trampling is a potentially effective tool to reduce YFI abundance. When greenhouse grown YFI plants reached 20-30 cm in height, two groups were "trampled" using a piece of 1.27 cm diameter electrical conduit. Treatments included trampling at the plant crown, trampling 1-2 cm above the plant crown, and a non-"trampled" control. Two months after treatment, we quantified plant survival and growth (height and number of leaves). We also conducted a field study to determine the effects of trampling on shoot density and height of YFI in the riparian area of the Niobrara River, at Agate Fossil Beds National Monument. Because permitting requirements prevented bringing cattle into the national monument in a reasonable timeframe, we implemented a citizen science project. The Harrison High School (Nebraska), Future Farmers of America Chapter, volunteered to help us trample YFI for the study. Sixteen 2x2 m study plots were randomly located in YFI infestations along the Niobrara River. Half of each plot was trampled in June 2015 and the other half was an untreated control. Iris density and height was recorded before treatment (May 2015) and three months after treatment (September 2015). Preliminary results suggest that a one-time trampling treatment significantly reduces both iris density and growth. Analyses are underway and this talk will report results from the field and greenhouse trampling studies.