About SinkholeOdds
Why this exists
Searching "is my house in a sinkhole area" mostly turns up news stories about one dramatic collapse, or a geology map with no plain answer attached. The question a buyer or owner actually has is narrower: does the rock under this county dissolve, how close to the surface is it, and is it worth paying for an inspection. SinkholeOdds answers that county by county from the USGS karst map, and says plainly where a county map stops being able to help.
What goes into the answer
Each county page measures how much of the county's land sits on each layer of the USGS Karst Map of the United States (Weary and Doctor, 2014): carbonate rock such as limestone and dolomite, evaporites such as gypsum and salt, and pseudokarst. Census county boundaries, land area and population estimates are joined on FIPS code. The full method, and its limits, are in the methodology guide.
A susceptibility map, honestly labeled
The USGS map shows where soluble rock lies. It is not a count of sinkholes and not a probability for any one lot, and this site never prints one. A county can be 30% karst while a given parcel is on none of it, or all of it. Every page says so.
Who runs this
SinkholeOdds is an independently run site. It is not affiliated with the USGS, any state geological survey, any insurer, or any inspection or foundation-repair company. If a page ever carries a sponsored link or referral, that is disclosed on the page itself and in the privacy policy.
Written by
County pages are generated by software, with AI assistance, from the cited USGS and Census data. No journalist or editor reviews each page before it publishes. The percentages come from the USGS map itself; the software only assembles the sentences around them.