The San Ysidro River runs through the San Juan valley, turning and twisting until it discharges sluggishly into Black Rock Bay under the protection of Bat Point.
The San Ysidro River runs through the San Juan valley, turning and twisting until it discharges sluggishly into Black Rock Bay under the protection of Bat Point. The valley itself is long and not very wide, and the San Ysidro River, having not very far to run, makes the most of what distance it has by moving from one side of the level stretch to the other. Here it cuts under a cliff, against a mountain, and then it spreads thinly out on sand-banks. During a good part of the year there is no surface water at all, and the sandy bed grows full of willows which stretch their roots down toward underground water.
