Update 3:55pm - Law Enforcement has located the pilot who is uninjured.
UPDATE 3:43pm- Authorities confirm that the plane has been located down in a field west of Castlewood. There is no word on the condition of the pilot as of this time.
KXLG news is continuing to follow a developing news story this afternoon out of Hamlin County. Hamlin County Sheriff Chad Schlotterbeck says this afternoon a pilot heard another pilot declare an emergency landing on his radio about 15 miles south of Watertown. Schlotterbeck says that no crash site has been located and he is asking farmers to search their land and report anything unusual to law enforcement immediately. Aircraft from Watertown and Pierre are enroute to the area to begin an aerial search. Ground resources are being assembled to begin searching the area.