"Tricky" parcel to do a cadastral survey on ?

Reminds me of something I worked on last year. Back in the 70's, several tracts were acquired by a timber company. For whatever reason, a 70 acre parcel was not shown on the tax maps as being acquired by the timber company. The previous owner, obviously, stopped paying taxes. So a few years later, the 70 acres was sold at a tax sale. The timber company, and its successors have paid the taxes on this 70 acres ever since, and the fellow that bought the property at a tax sale hasn't paid one red cent in property taxes.