Sinkhole Research
Florida
List of Florida Local Government Offices For Sinkhole Research – List of websites for County Property Appraiser and County Planning & Development / Building Dept. These sites are one of our data sources.
Florida Department of Environmental Protection – The DEP has a sinkhole map based on the data it gathers. It has limited parcel data but a good data source for cross-checking.
How many sinkholes are there in Florida?
Kentucky
How many sinkholes are there in Kentucky?
Missouri
Missouri Department of Natural Resources
How many sinkholes are there in Missouri?
Pennsylvania
Pennsylvania DCNA (Pennsylvania Department of Conservation & Natural Resources) – The DCNA has a database of sinkhole database.
How many sinkholes are there in Pennsylvania?
Tennessee
tnlandforms.us – The original data came from the United States Geological Survey.
How many sinkholes are there in Tennessee?
In General
http://www.plotscan.com/ – Search for sinkholes near the address you input. Does not provide data at the property level but is a good data source for cross-checking.
How NOT TO Buy a Sinkhole House in Florida? – Sinkhole Research 101  – This blog post is packed with information on how to carry out sinkhole research.
Others
http://www.floridapast.com – Came across this site while researching sinkhole history. If you love Florida historical souvenirs, this one is for you.