Narrative:

We had 1000 ft ceiling, visibility was 5-6 NM. Looked foggy ahead, turned around to go back, and the fog had encircled us. I decided my only option was to land in an open field. There was no damage to private property or aircraft.

Google
 

Original NASA ASRS Text

Title: A PA28 PLT, FLYING IN CLASS G AIRSPACE, MADE AN EMER LNDG IN A FIELD GETTING CAUGHT IN A FOG BANK.

Narrative: WE HAD 1000 FT CEILING, VISIBILITY WAS 5-6 NM. LOOKED FOGGY AHEAD, TURNED AROUND TO GO BACK, AND THE FOG HAD ENCIRCLED US. I DECIDED MY ONLY OPTION WAS TO LAND IN AN OPEN FIELD. THERE WAS NO DAMAGE TO PVT PROPERTY OR ACFT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.