Apo Reef Light control of the Philippines, all the Spanish plans and records were turned over to the United States. In 1903, the Bureau of Lighthouse Construction proposed to continue the construction of the third-order light on Bajo Apo Island. The tower was found in excellent condition at the warehouse by the Americans together with the tower for Capitancillo Islet in Bogo City, Cebu. A survey party was sent to the station in November 1903 for the topographical surveying of the Island as no work has ever been attempted yet by the Spaniards on this station—unlike in Tanguingui Island or Capitancillo Island where
Apo Reef protection and conservation work at the park, stays in the protected area on weekly shifts. The largest is Apo Island at with mangroves and beach vegetation. The reef surrounding the island extends to in places. Outside the lagoonal mangroves in the eastern and southern sides of Apo Island, the soil is sandy-to-sandy loam that is less in silt and clay particles. On the other hand, the lagoonal mangroves have a sandy loam to clay loam soil, underlain by decomposed plant residues or coarse materials. Apo Island is separated from Apo Reef by a narrow, deep channel. The island is about