I have a bunch of rainfall stations (point shape file) in a watershed (polygon shape file) and I need to find Thiessen Polygons. I tried to use 'analysis->proximity->Thiessen polygon' but the generated polygons cover only a part of the watershed. The script does not ask for the polygon shape file (watershed) which is to be allocated for each representative rainfall stations. Any suggestion or alternate script or tools for the task? I am using ArcGIS 10.