name of the region is "Papua" according to International Organization for Standardization (ISO). Independence activists refer to the region as "West Papua", while Indonesian officials have also used "West Papua" to name the western province of the region since 2007. Historically, the region has had the official names of Netherlands New Guinea (1895–1962), West New Guinea or West Irian (1962–73), Irian Jaya (1973–2002), and Papua (2002–present). The expected Indonesian translation of "Western New Guinea", Nugini Barat, is currently only used in historical contexts such as kampanye Nugini Barat "Western New Guinea campaign". Geography The region is from east to west and from north to south. It has an area of , which equates to approximately 22% of Indonesia's land area. The border with Papua New Guinea mostly follows the 141st meridian east, with one section defined by the Fly River. The island of New Guinea was once part of the Australian landmass and lies on the continent of Sahul. The collision between the Indo-Australian Plate and the Pacific Plate resulted in the formation of the Maoke Mountains, which run through the centre of the region and are long and across. The range includes about ten peaks over , including Puncak Jaya (), Puncak Mandala () and Puncak Trikora (). This range ensures a steady supply of rain from the tropical atmosphere. The tree line is around and the tallest peaks feature small glaciers and are snowbound year-round. Both north and west of the central ranges, the land remains mountainous – mostly high with a warm humid climate year-round. The highland areas feature alpine grasslands, jagged bare peaks, montane forests, rainforests, fast-flowing rivers, and gorges. Swamps and low-lying alluvial plains with fertile soil dominate the southeastern section around the town of Merauke. Swamps also extend around the Asmat region. The region has 40 major rivers, 12 lakes, and 40 islands. The Mamberamo river is the region's largest and runs through the length of Papua Province. The result is a large area of lakes and rivers known as the Lakes Plains region. The southern lowlands, habitats of which included mangrove, tidal and freshwater swamp forest and lowland rainforest, are home to populations of fishermen and gatherers such as the Asmat people. The Baliem Valley, home of the Dani people, is a tableland above sea level in the midst of the central mountain range. The dry season across the region is generally between