Kayak the Grass River. Paddle down the Grass River with a naturalist. MUST PREREGISTER, space limited. 2.5 hours. Reserve kayaks with paddles and pedals if needed. 231.533.4449, then call Grass River to register: 231.350.9461. Adults only. Grass River Natural Area entrance is located at 6500 Alden Highway, Bellaire, MI.