[3] The original district consisted of six buildings and additional infrastructure built using stone and concrete as construction materials.

[2] The Government of Puerto Rico added an additional 2.75 acres for the hatchery in 1940, and by 1942, the expanded fish hatchery facilities included large grow-out ponds for breeding fish (particularly brown and rainbow trout) and sixteen smaller ponds for breeding of crustaceans.

Reconstruction of these facilities were undertaken between the years 1998 and 2000 after considerable damages caused by Hurricane Georges, which devastated the island in September 1998.

Although the fish hatchery is no longer operational, this district retains integrity of location, setting, workmanship, materials, feeling and association.

The fish hatchery historic district includes 28 buildings, structures and resources, out of which 18 are inscribed as contributing properties.