Skagit River Systems Cooperative propose to complete two years of cattail monitoring at Fir Island Farms and one year of cattail control monitoring at Deepwater Slough, both of which are located at WDFW Skagit Wildlife Area in the Skagit River Delta near Conway, WA. Cattail control has been a tremendous success at the Fir Island Farms site, but needs to be maintained. Vegetation monitoring is critical to inform further cattail treatment, and the potential need to treat brass buttons (another invasive) if they also become a problem. This project builds upon work completed through ESRP project 14-2234, South Skagit River Delta Invasive Cattail Control. Through project 14-2234, WA Department of Fish and Wildlife conducted invasive cattail removal across 167 acres of estuarine delta habitat on the South Fork of the Skagit River, including Deepwater Slough, Wiley Slough, and Goat Island. Although the 2014 grant did not fund cattail treatment on Fir Island Farm, the treated areas were all located in close proximity to Fir Island Farm within the Skagit River Delta.