This dataset is to inform WSDOT and other state agencies of a known invasive species currently found in Washington State waterways. The New Zealand Mud Snail (NZMS) has been identified in a number of locations throughout the state. If in-water work is necessary within water bodies or connecting tributaries within a two-mile radius of the documented location (latitude and longitude), all personal gear (waders, tools, instruments, etc.) and heavy equipment must be fully decontaminated before being used at any other site. Transport to a secure site for cleaning/decontamination is allowed as long as precautions are taken to avoid any dropping of mud or debris between the work site and the cleaning/decontamination location.This dataset is used as a general reference layer for geographic information systems at the Washington State Department of Transportation (WSDOT). It is maintained by the WSDOT ESO office. Updates to this dataset are on an as needed basis.