Contains approximately 3111 irrigation water right permits on file with the Wyoming State Engineer's Office (SEO). They range in dates from the late 1800s to 2001. The water rights attribution task entails identifying and describing the water rights attached to the irrigated lands polygons. This task is included in the river basin planning process for two reasons. First, knowing the water rights attached to the polygons provides additional understanding of the source of supply and the irrigation systems that deliver water to the polygons. This increased understanding contributes to the accuracy and reliability of the service area designations used to group lands by source of supply. The second reason for the water right attribution task is to define the water resources of the basin. A description of irrigated lands is not complete unless it includes a definition of the water rights granted to allow for irrigation of those lands. The water right attribution process involves three steps: 1) land description development; 2) water right identification; and, 3) water right attribution. Each of these steps is discussed below. The product of the water right attribution process is a water rights database that includes identified water rights and their attributes. This database, when linked to the irrigated lands polygons through the Geographic Information System (GIS), allows the user to identify the water rights attached to the polygons of irrigated land.