In 1888 the colonial government proposed establishing 3 Indian reservations, with the western one covering Settlement 15, Settlement 238 and Settlement 6.[1]
Arenal was written as El Arenal in 1905.[2]
From at least 1906[3] to 1934[4] Arenal was a mission of the Church of Our Lady of Mt. Carmel in Settlement 15[5][6]; from at least 1936[7] to at least 1946[8] it was attended from the Church of the Sacred Heart in Settlement 231, and in 2026 its La Inmaculada Church was a mission of Our Lady of Mount Carmel parish in Settlement 15.[9]