OKLAHOMA CITY — Walton Construction Co. has been selected to build a new defense and logistics warehouse and distribution center at Tinker Air Force Base in Oklahoma City. The $20.4 million project will comprise a 165,000-square-foot warehouse incorporating a mechanized material handling system. The U.S. Army Corps of Engineers will be seeking LEED-Silver certification for the project, with sustainable features that include the use of local construction materials, high-efficiency energy systems and a reflective roof. Completion is slated for spring 2011. The project architect is Orlando, Fla.-based MRI Architectural Group.