San Mariano

San Mariano is a municipality in Isabela province in the northern part of the island of Luzon in the Philippines. Situated at the western slopes of the Sierra Madre mountains, it has a largely untapped ecotourism potential and is home to the only sanctuary of the endemic Philippine crocodile (Crocodylus mindorensis).

Founded in the 1920s, San Mariano occupies the western slopes of the Sierra Madre and is largely composed of forests and farmland. It is drained by the Ilagan or Pinacanauan de Ilagan River, a tributary of the Cagayan River. The municipality is also part of the Northern Sierra Madre National Park (NSMNP), encompassing the entirety of the mountain range within Isabela.

San Mariano has historically been a frontier town. The Spanish set up a mission in what was then a sparsely-populated area populated by indigenous peoples and outlaws in the 18th century. During the 20th century, it saw sustained migration by Ilocanos. In the 1970s, the area became a warzone when the New People's Army made the town its first major stronghold. At the same time, the town saw massive environmental devastation due to large-scale logging and unsustainable land conversion practices which was somewhat reduced by increased regulation in the 1990s and the discovery of a nesting ground of the endemic Philippine crocodile (Crocodylus mindorensis), locally known as bukarot, in 1999. This led to an increased awareness of the environment among residents and the establishment of the country's first sanctuary dedicated to the species.

The people of San Mariano are primarily engaged in farming, fishing and a small but gradually developing ecotourism industry. They speak a variety of languages including Tagalog, Ilocano and Ibanag. The town is also home to communities of indigenous Dumagats (Agtas) who mostly subsist on hunting, fishing and gathering from the forests.

San Mariano is bypassed by Maharlika Highway, the main thoroughfare in Isabela. Instead, it is connected to the road by a highway that runs from Naguilian Junction via Benito Soliven. It is served by jeepneys running from the provincial capital Ilagan and Cauayan, home to the nearest airport.

Tricycles and motorcycles are the main form of transport.

• 16.98308121.9754151 Philippine Crocodile Conservation Center (PCCC), Santa Filomena (inside ISU San Mariano), ☏ +63 920 974 2379, mabuwaya@yahoo.com. A conservation facility inside the campus of the Isabela State University dedicated to the care of the endangered Philippine crocodile. It is not exactly a zoo though, but rather a breeding facility for the species until they are fit enough to be released back into the wild. The facility also regulates access to areas where the crocodiles are known to inhabit in the wild.  (updated Oct 2026)
• 16.997547122.1597242 Dunoy Lake, Dibuluan. A brackish waterway, it is one of several spots in the vicinity where the Philippine crocodile can be found in the wild.  (updated Oct 2026)

Being inside the NSMNP, expect to see rare plant and animal species such as the pitcher plant while hiking.

• 16.981933122.0145921 San Mariano Public Market, Claraval Street, Zone II.  (updated Oct 2026)

The nearest accommodations are in Ilagan and Cauayan.

There may be a few NPA rebels in the mountains.

Philippine crocodiles tend to be more shy and are smaller than their more ferocious cousins, the saltwater crocodile (Crocodylus porosus), which has not been found in town. There are have been a few non-fatal attacks on humans and livestock since 1999 though, but are only limited to the vicinity of places where they are known to be present.

Avoid getting into a major medical emergency during your stay, as facilities and resources at the town's Community Hospital are limited. You will need to be taken to Ilagan or Cauayan at the very least for such an event.

The indigenous Dumagat communities still adhere to their precolonial customs and belief systems and are widely respected even by the non-Dumagat resident population. As they are the most experienced in dealing with the natural settings of San Mariano, you are expected to exercise maximum respect for their traditions and when visiting them.

The town's postal code is 3332.

Cellphone and internet signals can be weak in some parts of town.

• Ilagan
• Cauayan