El Cayo and Santa Elena were established in the mid 1860s as a baccadier or logging camp. Before 1949 the only access to the two towns was by boat up the Belize River or in the later years by plane. There was an airfield where the Macal River Park is now located.
In 1881 the Western District (now Cayo) was formed and El Cayo was made the capital.[1]
In the 1930s the construction of the Cayo Road was initiated, and by the 1940s the road had reached the twin villages. In 1949 the Hawkesworth Bridge was constructed, joining the two villages together. Thereafter the river traffic dried up and goods were hauled over the road from Belize City. In the 1980s the Western Highway was paved.
1978 - S.I. No. 47 Town boundaries defined.[2]
1981, October 20 - New town boundaries defined with a total area of 33.64 sq. km.[2]
2025, April 1 - all cities and towns in Belize had their boundaries updated. Santa Elena Town gave up some land to Cristo Rey on the east side of the Macal River and some borders in the Hillview area were slightly redefined. Meanwhile San Ignacio Town gave up land to Bullet Tree Falls and gained some land on the south west along the George Price Highway. In total the area was reduced by 2.3 sq km to 31.34 sq km.
Father Andrew Bavastro S. J., a Catholic priest, named the area San Ignacio in 1870. But in 1881 the Cayo District was established and the village was gradually renamed to El Cayo. In the past a creek ran between the Macal River and Mopan River one mile west of San Ignacio Town. This creek fulfilled the definition of an island (cayo in spanish).[3]
On October 19, 1904 El Cayo was officially declared a town as El Cayo Town.[3]
El Cayo was renamed in 1960 to The Twin Towns of San Ignacio and Santa Elena by the new mayor Hector Silva.[4]