Clast composition, flow direction, and U-Pb detrital zircon results from modern and ancestral rivers near Lewiston Basin, Washington and Idaho

This data release is companion to a manuscript entitled: "Long-term intermittent connection between the western Snake River Plain and Columbia Basin: a two-phased incision history of Hells Canyon". Here, we report the measured flow direction and compositions of clasts and detrital zircon U-Pb ages from samples collected from modern and ancestral rivers near the Lewiston Basin region. The data consist of clast composition measurements taken from modern and ancestral fluvial systems as well as flow directions and detrital zircon U-Pb ages analyzed from measured from the Miocene Clarkston Heights gravel.