A 26-km-long fault in southwest Oklahoma that has long been thought to be in active may instead turn out to be a relatively young fault. Primarily because of the lack of evidence indicating recent or historical earthquake activity, the Meers Fault, located near the Witchita Mountains and first mapped in the 1960s, was thought to have been inactive for as long as 300 million years. New data, however, suggests that the fault may have slipped within at least the last 10,000 years and possibly more recently (see Figure 1).