The city of Barreirinhas is considered the "gateway" to the Lençóis Maranhão. The origin of its name is linked to the mud walls (clay) existing on the banks of the Rio Preguiças (River). Because the walls, sometimes being polished by sand dunes, the region ended up getting popularly known as "Barreirinhas". This term, in its turn, was already used in the region in the late seventeenth century, well before the municipal creation.
In the 70's the city experienced the first outbreak of social changes caused mainly by the discovery of oil and gas potential of Barreirinhas block. It is considered as the first rapid growth spurt of the city, the emergence of neighborhoods like Canequinho, Cebola (Onion) and Airport. And in the 1990s there was a new growth spurt through the wide dissemination of the natural beauty of the region, such as the Lençóis Maranhão National Park, Caburé, Atins and Mandacaru.