Redd count monitoring data for Yellowstone cutthroat trout spawning in groundwater-fed tributaries to the Snake River, Wyoming

This dataset contains long-term redd count data for populations of Yellowstone cutthroat trout (Oncorhychus virginalis bouvieri) spawning in groundwater-fed tributaries to the upper Snake River, Wyoming, USA. Redd count data were provided by current Wyoming Game and Fish Department (WGFD) personnel or obtained from annual departmental reports. Annual reports can be made available from WGFD upon request. Some fields contain missing data (NA) in certain years and streams. Missing data typically occurs prior to the year 2000, before which robust departmental record keeping policies were in place. Redd count data were collected by the WGFD’s Jackson Fisheries Management Team between 1971 and 2021. Observers conducted a single redd count annually on the approximate date of peak spawning activity, typically in early July. Observers recorded the number and location of redds on maps of the spawning grounds following a two-step process. First redd clusters (single redds or multiple redds supimposed) were identified. Second, observers estimated the minimum and maximum number of redds in each cluster based on the number of distinct redd pots and the total area of gravel disturbance as compared to the average footprint of a single redd. For each stream and year, counts are summed to compute the total number of clusters, the minimum number of redds, and the maximum number of redds. The Wyoming Game and Fish Department reports the average number of redds ([minimum count + maximum count] / 2) as the official redd count in annual reports published by the agency. Surveys were conducted either along the entire stream from the mainstem confluence to the terminal headwaters or on pre-defined index reaches when access is restricted by private land ownership. A detailed description and evaluation of this redd count program can be found in Baldock et al. 2023 (https://doi.org/10.1139/cjfas-2022-0267).