Directions to OSU/Umatilla County Extension Service Directions to OSU/Umatilla County Extension Service Search | Advanced Search | New Members | Coupons and Discounts | All Categories Other >> Agriculture & Farm Markets OSU/Umatilla County Extension Service PO Box 100Pendleton, OR 97801 | map (541) 278-5403 Visit Site Get directions to: OSU/Umatilla County Extension Service, PO Box 100, Pendleton OR Get directions from: Click to Print This Page