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Federal
Attributes for NHDPlus Version 2.1 Reach Catchments and Modified Routed Upstream Watersheds for the Conterminous United States: Estimates of Subsurface Tile Drainage Extent for the Conterminous United States, Early 1990s
Department of the Interior —
This tabular data set represents the estimated percent area of subsurface tile drainage extent from the early 1990's compiled for two spatial components of the...