The 260-kilometre corridor linking São Luís Airport to Barreirinhas remains one of Brazil's most dramatic transitions from urban coast to raw interior. São Luís, a UNESCO World Heritage city founded in 1612, sits on an island encircled by the Parnaíba and Itapecuru deltas, its azulejo-tiled colonial core a relic of Portuguese mercantile ambition. Barreirinhas, by contrast, is a low-slung river settlement on the eastern boundary of Lençóis Maranhenses National Park, a 155,000-hectare expanse of crystalline dunes and seasonal freshwater lagoons that defies every convention of desert ecology. No scheduled bus service runs the route; the transfer from São Luís Airport to Barreirinhas is entirely privatised, conducted by licensed shuttle operators and independent drivers who navigate the BR-135 highway and the final unpaved stretch into town. The journey unfolds in three acts. The first hour follows the BR-135 south through cashew plantations and babaçu palm groves, the coastal plain giving way to dry plateau. At Rosário, the highway pivots east; here the asphalt begins to fray and the traffic thins to long-haul trucks carrying grain and cattle. The final 90 kilometres shed pavement altogether, becoming a red dirt track that winds through cerrado scrubland and crosses the Preguiças River on a car ferry that operates from dawn until dusk. The ferry crossing, brief and silent, marks the threshold of the park zone. Beyond it, Barreirinhas emerges as a grid of low concrete houses and riverside pousadas, the dune fields rising white and abrupt to the west. Transfer options divide into shared shuttles, which depart on fixed schedules and cost less, and private vehicles, which offer flexibility for early arrivals or families with luggage. Shared services typically seat six to eight passengers and require advance booking through operators who also run park tours; private transfers accommodate up to four passengers in air-conditioned sedans or vans. Both options include pick-up at the domestic terminal, where drivers wait with name cards near the baggage carousel. The road is maintained but rough; four-wheel drive is not mandatory but common. Travel time hovers near four hours in dry months, extending to five during the rainy season when the unpaved section becomes rutted and slow. Mobile signal fades entirely after Rosário, returning only upon arrival in Barreirinhas. The transfer is not scenic in a postcard sense—most of the route is flat, scrubby, and featureless—but it establishes the remoteness of the park and the effort required to reach it, a counterweight to the ease of the flight from São Paulo or Rio that precedes it.