Espinosa was on the Trinidad as part of Ferdinand Magellan's expedition, and called on the island while attempting to cross the Pacific Ocean to Mexico.

During this time, a private firm, the Pagan Society, owned by a German and a Japanese partner, developed more coconut plantations.

[6] During World War I, Agrihan came under the control of the Empire of Japan and was subsequently administered as the South Seas Mandate.

[10] An expedition organized by John D. Mitchler and Reid Larson made the first known complete ascent to the summit of this peak on June 1, 2018.

The entire island is a massive stratovolcano, called Mount Agrihan, which rises over 4,000 meters (13,120 ft) from the ocean floor, and is the fifth largest in the Marianas volcanic arc.

[12] The caldera floor has several lava flows and two volcanic cones, which were probably created during the April 1917 eruption.

Vegetation includes swordgrass (Miscanthus floridulus) grasslands on the upper slopes, forests of coconut palm (Cocos nucifera), with some breadfruit (Artocarpus altilis) and papaya (Carica papaya) on the lower slopes and within the deep ravines that descend radially from the summit.