You searched for: Institution University of Michigan. Libraries Remove constraint Institution: University of Michigan. Libraries Place O'Kean, about 2 miles northeast on Arkansas Highway 90 at Greene County Road 112 in roadside ditch between Hwy 90 & railroad. Remove constraint Place: O'Kean, about 2 miles northeast on Arkansas Highway 90 at Greene County Road 112 in roadside ditch between Hwy 90 & railroad.