ON A 105-DEGREE New York City afternoon, I hop on the #4 train and head north—past a good friend's one–bedroom on the Upper East Side, past a Harlem hangout that really kicks in the wee hours, and, continuing on aboveground, past Yankee Stadium in the Bronx. Until a few months ago, my only experience with the fourth borough was hobbling through it during the New York City Marathon: In the poverty–stricken neighborhood of Mott Haven, two women held up a homemade sign that read, WELCOME TO THE BRONX. THAT'S RIGHT, YOU BETTER RUN. Ha–ha, I thought, not knowing that "SoBro," as desperate realtors try to call it, remains one of the best places in America to get shot. I don't want to get shot. I just want to see a beaver.

Exiting at Bedford Park Boulevard, in the north Bronx, I stroll eight blocks southeast, past drivers futzing under the opened hoods of broken–down cars. I cross Kazimiroff Boulevard, a bustling four–lane, and enter the New York Botanical Garden. Its 250 shady acres, currently showcasing a collection of Henry Moore sculptures, border the Bronx Zoo to the south and lie just northeast of the shattered–glass ghetto of East Tremont. Inside the gate, the temperature immediately drops ten degrees.

Bob Heinisch, the well–dressed VP for site operations, greets me. "Do you need any provisions?" he asks as we hop into his golf cart and zip to the banks of the Bronx River, south of a low waterfall, in the Forest area of old native trees.

"OK," he says, vaguely gesturing that we've arrived at the spot while simultaneously checking his BlackBerry.

I step out onto the riverside path. The jungly little valley looks as good as any for a wayward beaver. I cowboy up onto the mossy back of an American elm that corkscrews out over the water. Then, quietly, I start calling. "Hey, buddy," I say. "C'mere, José."