Boise Airport Landscape Upgrades, Keystone Retaining Wall and Parking Modifications - To extend an existing retaining wall approximately 395 lineal feet east with new Keystone concrete block retaining wall. The retaining wall will vary in height from approximately six feet to twelve feet. The Keystone concrete blocks will be supported by a minimum 30 inch wide by 12 inch deep unreinforced concrete or compacted crushed stone base. There will be a crushed rock drainage system installed behind the retaining wall. This permit also includes associated adjacent asphalt parking lot modifications and upgrading some landscaping. The new work is being done east of the existing FAA Tower. All construction per the approved engineered plans and calculations. JCM