Sunday, Oct. 31 The Arkansas Historic Preservation Program will offer a free walking tour of Texarkana's historic residential area beginning at 1 p.m. Saturday. The tour is part of the Preservation Program's "Walks Through History" that are scheduled through noteworthy Arkansas neighborhoods and historic districts around the state. The first tour starts at 1 p.m. at the south steps of the Downtown Post Office on State Line Avenue in Texarkana at the most photographed spot in the Twin Cities-Photographer's Island. The walk will focus on the historic architectural and historic landmarks on the Arkansas side of the line but the Downtown Post Office is notable because it sits like a saddle on the state line, one stirrup in Texas and the other in Arkansas. Next the group will visit sites on the Arkansas side listed on the National Register of Historic Places: Foulke House, Wadley House, Whitmarsh House and Garrison-McLain House as well as other historic buildings in the neighborhood. The Texarkana Museums System will co-sponsor the tour, which is open to the public. The "Walks Through History" tours are held monthly. The final 1999 tour will take place Dec. 4 in downtown Jonesboro. Ken Story, the Arkansas Historic Preservation Program's outreach coordinator, leads each of the tours.