It might not look like much, but this unassuming bar is the oldest in Oklahoma. First opened by Peter Eischen in 1896, Eischen’s is still run by Peter’s descendants. Perhaps the bar’s longevity can be attributed to its sticking to the basics: The menu is literally eight items. They know what they do and do it well, especially their popular fried chicken. Their signature menu item was developed in the 1960s by George “Boog” Eischen, who also worked as a butcher at the IGA grocery store that once stood next door….