The province's geography runs from alpine grasslands to swampy lowland jungle. Mount Giluwe, straddling the border with Western Highlands Province, rises to 4,367 meters, making it the second-tallest mountain in Papua New Guinea and the fifth-tallest on the island of New Guinea. Its upper slopes carry evidence of past glaciation. To the south, the terrain drops through forested ridges to Lake Kutubu, the country's second-largest lake, known for its endemic fish species and its Ramsar Convention designation as a Wetland of International Significance. Still further south, the landscape flattens into lowland jungle dominated by the volcanic bulk of Mount Bosavi. These three landmarks, a glaciated peak, a biodiversity-rich lake, and an extinct volcano, mark the extremes of a province whose physical range is matched by its human diversity.

The linguistic map of Southern Highlands reads like a puzzle. In the west, around Nipa, Mendi, and the Lai Valley, speakers of Anggal Heneng dialects predominate. In the east, the districts of Kagua, Ialibu, Pangia, and Erave are home to speakers of Imbongu, Kewa, and Wiru. The lowlands from Mount Bosavi to Lake Kutubu include the Biami, Foe, and Fasu language groups. The Kutubu Bosavi people share ties with the Huli tribes and speak both Hela and the Foe Faso languages. The Erave Samberigi people trace coastal or Papuan descent. Around Mount Giluwe and Ialibu, the Umbu-Ungu dialect holds sway, while neighboring Pangia and Kagua each claim their own separate languages. Some tribal territories extend into Hela Province, Enga, Western Highlands, Gulf Province, Simbu, and Western Province, making every provincial boundary an arbitrary line drawn through living communities.

Beneath the highlands lie enormous reserves of natural gas, and their exploitation has shaped the province's modern history as much as any cultural force. Plans to construct a pipeline pumping gas to Queensland, Australia, were overtaken by instability in the region, prompting the national government to declare a state of emergency that drew criticism for restricting press access. The companies involved eventually redirected to the PNG Gas project, with export facilities near Port Moresby operated by Esso Highlands, a subsidiary of ExxonMobil. The 2018 earthquake, centered just across the border in Hela Province, forced shutdowns at both ExxonMobil's Hides gas plant and Oil Search operations across the Southern Highlands, demonstrating how tightly the province's economy is tied to extraction and how vulnerable that economy remains to the geological forces beneath it.

Southern Highlands has a turbulent political history that reflects the intensity of its tribal allegiances. In August 2006, Prime Minister Michael Somare declared a state of emergency in the province following accusations of corruption, theft, and misuse of government buildings by the regional government. The 2017 election for provincial governor became a legal battle when challenger Bernard Peter Kaku sued Governor William Powi, alleging premature declaration of victory without a majority. In 2021, the National Court ruled in Kaku's favor and suspended Powi until a recount could be completed. The 2022 election brought open violence, with fighting erupting in Mendi between supporters of Powi and rival candidates. The pattern is consistent: in a province where tribal identities run deeper than party affiliations, every election tests the limits of the democratic process.