Ambulance|Los Angeles River, Elysian Valley — The Grey Trench Every Chase Ends In

Every Los Angeles car movie eventually falls into the river. Grease, Terminator 2, Drive, Repo Man, To Live and Die in L.A. — the concrete channel is the city's default final act, and Ambulance takes its turn, the stolen rig running the flat bed with helicopters stacked above it.

The reason is engineering. After the flood of 1938 the Army Corps of Engineers lined fifty-one miles of the river in concrete, producing a dead-straight, obstruction-free corridor through the middle of a city that has almost no straight lines. It is a road that was never meant to be one. Drop a camera into it and the ambulance has nowhere to hide and nowhere to turn.

The Elysian Valley stretch — Frogtown, between the Glendale Freeway and downtown — is the accessible one. Water actually runs here over a soft bottom the Corps could not pave, so there are willows, herons, cormorants, and a rough green line down the middle of all that grey.

The Los Angeles River Bike Path runs about seven and a half miles along this bank, open dawn to dusk and free. Enter at the Fletcher Drive Bridge and ride south. Stand on the path where the channel walls flare out and you understand it in one look: a two-hundred-foot-wide floor of concrete, empty, aimed straight at the skyline.

Photo: "322 Fletcher Drive Bridge Over the Los Angeles River" by The City Project, CC BY-NC-SA 2.0 via Flickr.