[1] Its primary headwaters are in the portion of Timor-Leste's central mountains located within the southern ends of Nitibe and Oesilo administrative posts in Oeucusse.

[5] The bridge connects Citrana, Passabe and other isolated regions west of the river to Oecusse's capital, Pante Macassar, providing them with permanent access to markets, the ferry, and airport, even during the rainy season (November to April).

Between 1512 and 1515, Portuguese traders were the first of the Europeans to arrive in the area; they landed near modern Pante Macassar, about 5 km (3.1 mi) to Lifau's east.

[8][10] In 1769, the capital of Portuguese Timor was transferred from Lifau eastwards to Dili, due to frequent attacks from the local Eurasian Topass group.

[12] As is the case throughout the Indonesian archipelago, human settlement in Oecusse, including in the Tono River catchment or drainage basin, has traditionally been concentrated in the mountainous interior, rather than near the coast.

There are many likely reasons for this tradition: for example, altitude offers relief from coastal heat and much lower rates of malaria infection, and high ground is easier to defend against invaders.

In Oecusse, areas of higher altitude also benefit from substantially greater rainfall over a rainy season that can be two months longer than along the coast, and groundwater reserves are more plentiful.

[17][18] In 2013, the government of Timor-Leste appointed former prime minister Mari Alkatiri to oversee the development of a special economic zone in Oecusse.

The plan comprised a substantial number of proposed buildings and capital investments, including a 380 m-long (1,250 ft) bridge over the Tono River on the coastal road between Pante Macassar and Citrana.

By September 2017, the government had spent approximately US$10 million of that total amount, on rehabilitating and upgrading the Tono irrigation scheme, in particular by building a dam to provide more water, more reliably.

[13]: 22  In general, inheritance of land and property in the exclave is patrilineal, but in the lowlands, female ownership of irrigated rice fields is common and men will move into their wives' homes upon marriage.

[13]: 12 [28] Agricultural or agro-forestry activity in the catchment is made difficult by its dry climate, poor soils and challenging topography, which is generally mountainous with little flat land for large-scale cultivation.

Oecusse’s sandalwood reserves, unlike those in the rest of Timor, were still substantial in 1975, but were then rapidly depleted, largely by more intrusive, and often corrupt, Indonesian logging practices.

They prefer to use livestock as a store of wealth that can be used, eg, to pay a bride price or as insurance against food shortages, and rarely slaughter cattle for their own consumption.

Since 2002, however, difficulties in marketing cattle in Dili, and the effective closure of the borders to West Timor, have presented very substantial obstacles to the export of livestock.