Median discharge and median water temperature during June–August (N = 92 d; 2004–2010, 2012–2016) for the Missouri and Yellowstone rivers used in correlation analysis of catch per unit area (CPUA; number/m2) of age-0 Macrhybopsis, age-1+ Sturgeon Chub Macrhybopsis gelida, and age-1+ Sicklefin Chub Macrhybopsis meeki. Numbers in parentheses are the first and third quartiles of the data distributions; for temperature, D indicates the number of days during June–August that water temperature equaled or exceeded 18.0°C. Discharge data were obtained from Missouri River U.S. Geological Survey (USGS) gaging station 06177000 located at river kilometer mile (rkm) 2,739 and Yellowstone River USGS gaging station 06329500 at rkm 47.0. (The 0-rkm point was the confluence of the Missouri and Mississippi rivers.) Water temperature data were obtained from water temperature loggers deployed in the Upper Missouri River (rkm 2,814), lower Missouri River (rkm 2,561), and Yellowstone River (rkm 4.0).