Geomorphic Surface and Channel Boundaries for the Lower 7.5 Kilometers of the Taiya River Valley, Southeast Alaska, 2018

The USGS mapped geomorphic features in the lower 7.5 kilometers of the Taiya River valley bottom in and near Klondike Gold Rush National Historical Park near Skagway, Alaska. This dataset presents delineations of off-main-stem channels and geomorphic surfaces. Boundaries were prepared from 2003 lidar elevation data and updated using 2017 and 2018 aerial orthophotographs at eroding riverbanks, such that the dataset generally represents 2018 conditions. Channel attributes include physical and hydrologic conditions related to water sources and were determined from 2003, 2017, and 2018 aerial imagery and field observations. Interpretations of surface age primarily used 2003 lidar data and aerial imagery from 1948 and 2003. Mapped surfaces consist of the 2003 active main stem (Taiya River and West Creek wetted channel, bars, islands, and major sloughs), additional areas recruited to the main stem by 2018, main stem surfaces abandoned between the 1940s and 2003, main stem surfaces abandoned prior to the 1940s, alluvial fans, and emergent tidal flats.