At 24,000 acres, Sauvie Island in the Columbia River is one of the largest river islands in the nation. It lies about 10 miles northwest of Portland and extends 14 miles north, to St. Helens, Oregon. Its average elevation is just 20 feet above sea level. The island’s southern portion, scenic and rolling farmland, has been diked to protect it from river flooding. The northern portion, managed by the Oregon Department of Fish and Wildlife, is wilder: 11,543 acres of lakes, sloughs, a winding river and numerous channels, ideal for boating. The Multnomah Channel, a quiet ribbon of water, runs along the island’s west shore, from the confluence of the Willamette and Columbia rivers to the island’s narrow northern tip.

Note: A Sauvie Island Wildlife Area parking permit is required at areas under ODFW control. Purchase permits at the general store on the island, just north of the Sauvie Island Bridge. Access to the Multnomah Channel is year-round; access to waterways on the island is not allowed, in general, from October 1 to May 1.

I like to anchor the boat at a Sauvie Island backwater, among beaver and deer and the scritch and grawk of birdcall at the edge of city limits. I mean…here we are, in the greenest metro area of the richest nation on earth. And I wonder, sometimes, whether or not we can save what makes the Portland/Vancouver area unique. From my boat, the Willamette and Columbia rivers look and smell clean. I swim in them both; always have. But I am haunted by warnings: do not eat the bottom fish. In the paper I read sickening reports of one-eyed fish with crooked spines, and of river otters with withered genitalia.

One morning, when the sun rose high enough to catch the bank, a small river otter emerged from cottonwood roots and slid into the water. Then another slid down the mud bank. And another. Five, in all, liquid black and glossy, climbed back up the bank and went skidding down, nosing into the water without a splash.

Otters are curious. They come whistling up close for a look at a queer boat that’s not moving. And otters play. Why the hell not?

These otters started wrestling in the water. They made an otter ball of themselves. Heads over tails over heads over tails, the otter ball went churning along the surface, throwing up spray. When that got old, they dived and surfaced separately. One little showoff came up beside the boat with a crawdad between his teeth. He cracked and ate the crawdad.

When I glanced up, I saw the otters’ parents. They had come out to watch, and to watch me watching.

And I felt, for my own crowding species, on the spot.