ArcView's snapping environment allows a feature of a theme to be snapped to another feature within the same theme. It does not snap to a feature in another theme. Instructions provided describe how to add theme-to-theme snapping tools to ArcView.
Get the Snap2Other extension from the ArcScripts Web site. Click the associated link in the Related Information section and do a keyword search for 'Snap2Other'. Download and install the extensions.
There are other snapping tools available from the ArcScripts Web site. If Snap2Other doesn't provide what is necessary, try one of the other tools.