Riverbend Restaurant Office Address: 200 S 2nd St, Mammoth Spring, AR 72554 Phone: (870) 625-3539 Restaurants Other Businesses: Riverbend Restaurant Office at 200 S 2nd St, Mammoth Spring, AR 72554 Mammoth Spring Floral Express at 228 Main St, Mammoth Spring, AR 72554 SONIC Drive-In at Highway 63 @ Hill Street, Mammoth Spring, AR 72554