Adventure Rents operates its kayak and canoe livery on the peaceful and pristine Gualala River that forms the boundary between Sonoma and Mendocino Counties in northern California. The Gualala River is backed by thousands of acres of private forest. Unhurried and undeveloped along its entire length, the Gualala River watershed supports an abundance of wildlife, including numerous waterfowl, osprey, mink and river otter, and is protected from motorized watercraft, providing a perfect setting for safe, self-guided paddling, past redwood forests, salt marshes and sandy beaches. In summer, the sand at the mouth of the Gualala River builds up naturally until it closes, becoming a natural dam through which the river and ocean filter with the tides. This phenomenon occurs somewhere between mid-May and early July. When the mouth closes, the water backs up for several miles creating an elongated lake with imperceptible current, perfect for novice boaters, and turning the river estuary into a closed lagoon. In late fall, the first major storms open the river mouth for the duration of the rainy season.