Historical Data Browser (HDB) allows the users to perform queries against the data inventories, review the results both in geographic and graphical displays, display and plot the actual data, and when satified, produce data sets formatted appropriately for subsequent use.

In response to a particular query, the HDB will display all stations satisfying the specified conditions and display them on a map background.

The user can select stations from the geographic display and show information about the station as well as display the data.

The Office of Hydrology maintains the raw historical data centrally, and the HDB and the inventory files are distributed to the field offices. This distribution mechanism allows each office to preform inventory queries rapidly at the local site and then retrieve the data from the central repository without the need for replicating the data itself. The HDB itself deals with the physical location of the data and makes it transparent to the user.