Data collected from June-October 2020 on redband trout (O. mykiss giardneri) from south-western Idaho. Fin clips and gill biopsy samples were collected and are housed at conservation genetics lab at Idaho State university. Variables prefix: Sample archive prefix, RBE = Rainbow Epigenetics sample_ID: Individual sample number, unique to each fish length: fork length in mm mass: total mass in grams stream: location of population sampled air_temp: air temperature recorded at sample sites in degrees C month : month during which sampling event took place julian_date: date during which sampling event took place time: approximate time in which samples were collected, military time