This dataset provides a synthesized national record of river gauges. It includes inferred flows which are based on the structure of the river network and empirical flow relationships. In total, the network contains 22619 gauges (or virtual junction gauges) and over 1 million years of monthly data. The dataset is provide as a saved data file for R, flowdata.RData, containing two variables: nodes and allflow. `nodes` describes each gauges or virtual junction gauge in the water flow network, representing a combination of gauges from multiple sources. The source is specified by the `collection` column, as follows: `rivdis`: From the RivDIS dataset, at http://iridl.ldeo.columbia.edu/SOURCES/.UNH/.CSRC/.RivDIS/index.html?Set-Language=en `usgs`: GAGES II river gauge `reservoir`: National Inventory of Dams reservoir `usgsres`: USGS gauged reservoir `canal`: Canal cross county boundaries `junction`: Junction node added to capture the structure of rivers from HydroSHEDS The `colid` specifies the ID of the gauge within its collection, and combined `collection` and `colid` are unique. The location of the gauge is specified by the latitude `lat` and longitude `lon`. The elevation is provided in meters in column `elev`. The flow data is contained in the `allflow` matrix. This matrix has a column for each node (as many columns as there are rows in `nodes)`, and a row for each month starting from Jan. 1915. All the flows are in units of m^3 / s.