MY FRIEND Jeremy and I are baby-stepping down a path—gingerly, oh so gingerly, because by “path,” I mean a jagged scar through a vertiginous deathscape of blackberry brambles, undoubtedly forged by a secretive and murderous cult—into a narrow ravine near the banks of the Willamette River.

“Maybe we’ll disappear down here,” Jeremy says. “Maybe we’ll be forced to live wild.”

“And the Discovery Channel will come in to find us,” I say.

Unofficially, we’ve just crossed a sharp psychic boundary, one that divides the precisely landscaped residential streets of the Overlook neighborhood from menacing botanical anarchy. Officially, we’ve entered Mock’s Crest, one of two expansive bluffs that make up the area called the Northern Willamette Escarpment, 200 acres of weedy North Portland acreage that stretch along the east side of the river from around the Fremont Bridge up to St. Johns. It’s the ridge that thrusts North Portland above the rest of the city, an amorphous green enigma rearing up above the Union Pacific rail yard and the traffic that rockets down N Greeley Avenue and N Interstate Boulevard.

I’ve wanted to explore this place for some time now. My wife and I often walk through Overlook, which isn’t far from our house off of N Mississippi Avenue. To me, Overlook has always seemed to be the perfect distillation of “Portland Nice”: It’s home to a weekly farmers market and a couple of expansive parks, and it’s just a healthy stroll away from coffee shops, restaurants, a MAX light-rail line, and other home-resale-value-enhancing amenities.

But then there’s this steep plunge into tangled quasi-wilderness to the very immediate west, which I guarantee does not receive prominent play in real estate ads. Periodic signs of human activity along the escarpment’s upper edge paint a less-than-benign picture: bushwhacked trails cutting down into darkness, littered with empty booze canisters.

We’ve crossed a psychic boundary, one that divides landscaped streets from botanical anarchy.

During my humble family excursions, I eye those trails with both fascination and leeriness. We Portlanders are justifiably proud of our trophy green spaces—the Forest Parks, the Powell Buttes, what have you—and the way they embody our city’s crunchy harmony with nature (or, at least, with nature trails). We love our urban wilds, but we prefer them well-maintained, recreationally accessible, and without that murderous-secret-cult vibe. Within the Portland family of parks, the Willamette Escarpment is the second cousin who has three teardrops tattooed under his left eye and who starts recounting Measure 11 offenses after a couple of drinks.

What could be down there, I wondered? A colony of hyper-evolved, iridescent spiders the size of Toyota Scions, communicating via telepathic vibrations? A village of neo-Druids on a prolonged bad trip that started in 1967? Anything was possible. I pictured myself in a pith helmet, machete in hand, plumbing the escarpment’s hidden depths. However, given the prevalence of alcohol-related detritus, it also seemed plausible that any humans I encountered might not appreciate a slumming middle-class idiot wandering through an area that any other moron would recognize as obviously Off-Limits. So I recruited Jeremy, a highly capable (he can build things and so forth) and physically formidable (he thrashes me in racquetball) pal. Should any denizens cut up rough, Jeremy could protect me, I wagered. Or, at least, I could bargain his life for mine. And so we locked our bikes to a streetlight pole in Overlook and plunged in.