This dataset summarizes selected basin and streamflow special conditions for USGS streamgages in Alaska that are commonly used for site and period of record selection for regional analyses, through water year 2022. The data consist of a table providing information about the type of streamflow available for the site, site special conditions related to the timing of data collection, basin special conditions related to drainage area and urbanization, and a summary of water years for daily mean streamflow and annual peak streamflow affected by regulation or outburst flooding. The data were compiled using peak-streamflow codes assigned in the USGS National Water Information System (NWIS; https://doi.org/10.5066/F7P55KJN),...