Eufaula is a city in Barbour County, Alabama, United States. There is no city named Eufaula in Oklahoma.
The name likely causes confusion because Oklahoma has a Lake Eufaula (also called Eufaula Lake), a large reservoir on the Canadian River created by Eufaula Dam. The lake and dam are named after the Alabama city—or possibly the Creek town of the same name that once stood nearby.
So if you're measuring distance to "Eufaula, OK," you're probably thinking of the lake, not a municipality.