Wells as an Irrigation Source on Agricultural Land in the Conterminous United States, 1992:
National Resource Inventory Conservation Practice IS01
This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the 
agricultural conservation practice (CPIS01), Wells as an Irrigation Source (WIS) on agricultural land by county.  
Wells as an Irrigation Source are described as a "hole drilled or bored into the earth …