The other day, I wandered over to the corner of West Burnside Street and Northwest 17th Avenue to look at the Tanner Creek Interpretive Center, otherwise known as A-Ball Plumbing Supply.

Opposite the pull-ring shower A-Ball has thoughtfully pulled onto the sidewalk for the crew of the Tanner Creek Stream Diversion Project, a cityscape from the late 1800s is taped to a plate-glass window. Tanner Creek flows alongside the Great Plank Road (now the Sunset Highway), winding through the Kings Hill neighborhood and past a tannery (now PGE Park) before disappearing beneath a V-shaped bridge spanning a deep ravine at Alder and Burnside.

On the other side of the glass, arranged around a vintage clawfoot tub, sit chunks of redwood from the Alder Street Bridge and other artifacts recovered from the excavation project, which has West Burnside closed between 14th and 19th avenues. The tub's shower curtain is decorated with a series of black-and-white photographs, circa 1917, of workers laying the final sections of the sewer pipe that now carries Tanner underground from the West Hills to Columbia Slough.

Leaving A-Ball, I peered into the trench where workers (this time without handlebar moustaches) were burying concrete pipe that, come January, will carry Tanner Creek away from the municipal sewer system and deposit it back into the Willamette near its historic delta, downstream from the Broadway Bridge.

All this got me thinking about the Tanner Creek Hiking Club. Fifteen years ago, a guy I'll call Todd found an old sewer map in the city archives. Being the urban adventurer he is, Todd decided to pay Tanner Creek a visit. One bright afternoon, after hoisting a few at the Kingston Bar & Grill, Todd and a few drinking buddies heaved aside a manhole cover near the stadium, switched on their headlamps, climbed down a ladder, and stepped into Tanner Creek. In the dank darkness, it swirled around their knee-high-rubber boots, contaminated with toilet paper, tampons and turds.

"It seemed like a crippled old creature," Todd told me recently. "But somewhere, in all that gray slime, amid the rats, that pristine creek was still there."

They followed it, stooping through a narrow pipe, stepping into a cathedral-like cobblestone chamber, walking toward an ominous roar, until they arrived at the Major Sewer Interceptor, a city-sized toilet bowl, where they watched wide-eyed as Tanner Creek disappeared down a swirling vortex nine feet wide and 20 feet deep.

As I crossed Southwest 18th Avenue at Salmon, I kneeled at the curb and put my ear to a sewer grate. Out of the darkness, the crashing stream called to me, like a lost child.

It was one of the saddest sounds I have ever heard.

The Tanner Creek Interpretive Center (A-Ball Plumbing Supply, 1703 W Burnside St., 228-0026) is open 9 am-5:30 pm Mondays-Fridays, 10:30 am-4:30 pm Saturdays.

For more information about the Tanner Creek Stream Diversion Project, call Bob Cynkar at the Bureau of Environmental Services, 823-7898; .