The JBLM-McChord Field Main Gate and Visitors Center is located off I-5 from Exit 125 (Bridgeport). Use the left lane for access to the Visitors Center.
Joint Base Lewis-McChord is a controlled access installation. Vehicles with an adult authorized ID cardholder may enter JBLM through any open gate. Commercial vehicles visiting the installation should enter the McChord side through the Commercial Vehicle Inspection Point Gate. During those hours when the McChord CVIP gate is closed, commercial vehicles process at the Madigan Gate. Vehicles without an adult Authorized ID Cardholder present must report to the Visitor Control Center adjacent to either Liberty Gate or McChord Main Gate to receive a pass. In order to receive a pass, you must have your driver's license, vehicle registration and proof of insurance.
Source: Gate Information Website