If we had fulfilled to the letter my lifelong wish of traveling the length of the border, we would have headed straight south from Jimaní to that last pairing of sister towns, Pedernales and Anse-à-Pitre. But to do so we would have to traverse another sierra, Bahoruco, on a remote road whose condition Amadeo’s contact hadn’t gotten back to him about. It’s also a major area for smuggling, not primarily drugs, as I imagined. According to Amadeo, some 30 percent of the Haitian coffee crop comes into the Dominican Republic as contraband along this corridor. We decided not to risk it. After all, bucket-list travel should be something fun you do before you die, not something you might die doing.

So we took the longer, safer route, down the east coast of the Bahoruco Peninsula to our last stop, Pedernales. Most of the peninsula is a national park, a reserve for endemic species, including more than 150 species of birds, a birder’s paradise. At Bahía de las Águilas, we met up with a group of the birders, led by Rockjumper, a touring company for birding adventures. Two older gentlemen, who looked like extras for a movie about the British Raj (khaki-colored short pants, knee socks, safari hats, sunburned faces), hurried down a hill to announce that they’d spotted a flock of Caribbean martins. This had the effect of setting off a fire alarm in a high school lunchroom: Everyone made for the exit. Except for one Rockjumper who stayed behind enjoying something else she wouldn’t get midwinter in Wisconsin: fresh conch cooked in a criollo sauce.

Pedernales, like Jimaní, was also a town that received the steroids of Trujillo’s Dominicanization crusade. Inhabitants were lured with promises of land, jobs, weekly subsidies (10 cents a head for each child). But unlike Jimaní, Pedernales was too remote to become an important border crossing. Instead, it has maintained a sweet, untampered quality, as if it still remembers its roots as a fishing village, and its grander pre-Columbian history as part of Jaragua, the largest of the five caciquajes into which the island was then divided. Its name, in fact, means flint, from the local stone the Taínos shaped into cutting utensils and arrows. A few years back, when Alcoa pulled out its nearby bauxite operations, Pedernales went into a steep decline; the lightweights left, and those who stayed mined a deeper, richer resource: a vast expanse of unspoiled nature. With that discovery came a fierce sense of stewardship.