These data were complied for the primary analysis underlying the resuts presented in Neher et al., Testing the Limits of Temporal Stability: Willingness to Pay Values Among Grand Canyon Whitewater Boaters across Decades. The data is a combination of data collected for a 1985 survey of private party Grand Canyon boaters, and a 2015 replication survey for that same recreational user group. The excel file contains the core dichotomous choice contingent valuation questions and responses from the two (1985 and 2015) surveys. A series of indicator variables are used to delineate the underlying survey source (1985 or 2015 data) and the flow level presented to respondents (5000, 13,000 22,000 or 40000 cfs) The CV bid levels for the 2015 survey data have been deflated using the CPI-u to be consistent with the 1985 price levels. Bid levels from the 2015 survey data (IDs 1000-1414) may be reinflated to 2015 $ by multiplying them by 2.2177 (CPI-u (2015) / CPI-u (1985)).