Most of what we now think of as 'Los Angeles' used to be wild grassland, cut through with creeks and arroyos that drained out of the mountain ranges that define the basin.

The creeks are all still there, you know, you just don't see them. Some were lined in concrete and disguised as storm drains, or hidden underground. A few show up in backyards, on the campus at UCLA and the fairways at Wilshire Country Club.

The splashes of yellow mustard you see growing in vacant lots, like the foxtails that stick in your socks and prickly pear cactus, are all urban survivors of the old days.

They're mentioned in historical accounts of the settlers and city builders who created the mass assemblage we call L.A. out of a vast region of ranchos and scattered towns.

This week I was driving home late one night and came across a raccoon on the sidewalk. Not in the hills, but on a city street in the flats of Mar Vista.

He was fat and looked unconcerned by my presence as he went about his nighttime business. It may have been the same one that climbed up on my back deck a few months ago to get a closer look at some raspberries.

Another survivor, like the possums that crawl through the L.A. night by the thousands.

I got to ruminating on all this because of two stories I read. One was the report that a woman on her morning run was bitten by a coyote. She was near the carousel in Griffith Park, and a trash can nearby had been toppled over.

Rangers speculated that the runner had spooked the coyote while it was hungry and maybe a little irritable. So it nipped her. There are so many coyotes in Los Angeles and surrounding cities that I'm surprised it doesn't happen more often. Just as it probably did when the chaparral that makes Griffith Park so attractive used to be found pretty much everywhere.

The other story that caught my attention grows out of the running controversy over whether the Los Angeles River should be classified by the federal government as a navigable waterway. The Army Corps of Engineers, keeper of the river since the 1930s, wants to declare it not a real river, reducing its protections under the law.

A program manager for the agency protested by kayaking on a piece of the river deemed not navigable, and found herself getting suspended.

The LA River is always being dismissed by somebody -- for obvious reasons. To a casual observer it doesn't look like much more than a channel of concrete.

But for any student of L.A., the river is a dominant feature. It's fed by springs and natural runoff, as well as by the icky stuff that washes off the streets.

For more than a century it was the water supply for Los Angeles. Its steelhead run was a source of food. There are still fish to be found in the pools that form along its course from the Simi Hills at the west end of the San Fernando Valley down to Long Beach.

That's 51 miles of river, with a bigger drop than on the entire Mississippi.

Floods on the great Los Angeles has killed hundreds of people and inundated wide swaths of the city through the years. That's why so much of it is now concrete.

But every so often, a reporter or an activist will stick in a canoe or a kayak or a raft and prove that the river still exists. Navigable or not, the LA River is here to stay. History tells us that much.

For KCRW, this has been Kevin Roderick with LA Observed.