A stream is an expression of its watershed; that is, liquid is literally “expressed” from an ecological matrix, the green breast of Earth, to form a flow confined by discernible banks. A stream’s water originates in snow, spring, and rain. At its head, it may ooze from a muddy slope; at its mouth, it spreads wide and gives itself to another body of water— a lake, a river, an ocean, or even another stream. Its velocities are various: it can flow in ribbons, braids, or as flat as a scarf. Sometimes a stream runs underground or deep in the Earth’s surface, as in Typee, where Herman Melville writes: “Starting to my feet, the sight of those dank rocks, oozing forth moisture at every crevice, and the dark stream shooting along its dismal channel, sent fresh chills through my shivering frame, and I felt as uncontrollable a desire to climb up towards the genial sunlight as I before had to descend the ravine.” A stream can also, eventually, cut through rock like a blade. A stream always moves under the spell of gravity. It is a medium for transport—silt, pollen, pine needles, and leaves float its rapids and riffles and are deposited in its bed. Under the water is that streambed, all rock-and-roll, a home for sediment and rock and a nesting ground for fish. Steelhead, trout, and salmon lay their eggs one to three feet deep in a gravel redd, while benthic invertebrates such as stoneflies, mayflies, blackflies, and caddis flies hide in a stream’s cobbles. A stream is dynamic—and it receives, and thus reflects, the abuses that have taken place on the land.

Gretel Ehrlich