State Line Diner 375 State Rt 17, Mahwah, NJ07430 The aptly-named State Line Diner is located on Route 17 North but is also accessible from its back entrance on Island…More Avenue. This 24-hour eatery serves traditional feel-good favorites like hamburgers, fries, tuna melts, gyros, breakfast platters and much more. They also have an in-house bakery and bar. Mahwah residents and visitors frequent the State Line for breakfast, lunch, dinner, late-night snacks, desserts and drinks. It has a friendly atmosphere perfect for a family dinner or business lunch meeting.