Monitor Frequency of Non-Native Rainbow Trout Genetic Introgression in Native Westslope Cutthroat Trout in the Stehekin River. NPS In 2001, 2002 and 2010 fish tissue samples were collected at Stehekin River locations distributed throughout the drainage to monitor the level and frequency of hybridization between non-native XXX and native WCT. Results indicate that there has not been any significant change in the frequency of WCT, XXX, and hybrids between 2002 and 2010 at any of the locations sampled. It is recommended that we continue to monitor genetic introgression every five to ten years to evaluate the status and progress towards WCT restoration in the watershed.
