Also you didn't specify what system you're hearing this on so I'll assume
ISICS. Being that at least one talkgroup in the "337XX" series has been identified for Jasper County and "37XXX" for Kossuth County, numerically it'd make sense for a "334XX" series talkgroup to possibly be Jackson County (Jackson comes before Jasper alphabetically) as the higher numbers seem to correspond to the higher letter county names. Keep listening to any unknown talkgroup you encounter for any identifiable information (street names? business names?). Use
Google Maps if need be to research locations & once you're confident you nailed the user down,
submit the info to the database!