San Martín

Department in north-central Peru, west of the large department of Loreto, from which it was separated in 1906; area 51,253 sq km/19,789 sq mi; population (1996) 643,233. The capital is Moyobamba, but the most important town in the department is Tarapoto. San Martín lies mainly in the hot tropical valley of the River Huallaga, a tributary of the Amazon, which crosses the department from south to north, but the region also extends in the west into the foothills of the Andes. Tobacco is the main crop of the region, accounting for about half Peru's total output. Rice, coffee, and tropical fruits are also grown in the settled areas along the Huallaga known as Tingo Maria-Tocache-Campanillas.

The department takes its name from José de San Martín, the Argentine general and liberator who declared Peru's independence from Spain in 1821. In the west of the department are the remote archaeological ruins of Gran Pajatén.