Keningau sits in the Interior Division of Sabah, surrounded by the Crocker Range and the peaks that define Borneo's mountainous spine. During the colonial period, the town served as an administrative outpost, and the rest house provided accommodation for officials traveling the difficult routes through the interior. After North Borneo became part of Malaysia in 1963, the building's purpose evolved. By 2008, it had been converted into the Keningau Heritage Museum, preserving not just the physical structure of colonial administration but filling it with the cultural and historical materials of the people who had lived in these mountains long before any colonial power arrived.

The museum's most significant acquisition arrived in September 2018, when the Keningau Oath Stone was relocated to the museum grounds after years of political controversy. The stone, carved from a boulder pulled from the Pegalan River, records the constitutional guarantees made to Sabah's people when the state joined Malaysia: freedom of religion, state authority over land, and respect for native customs. Words had been tampered with on the original monument, and the restoration and relocation became a cause that consumed Sabah's political establishment for years. Its placement at the museum, with the three missing words restored, gave the stone both a permanent home and a new generation of visitors.

In 2015, the museum received a donation that connected two unlikely histories. A former Australian soldier who had married a local indigenous woman and settled permanently in Sabah donated wartime and personal artifacts to the collection. His story, of a foreign soldier who came to Borneo during the war and never left, mirrors the broader theme of the museum: that Keningau's history is not a single narrative but a collision of cultures, armies, colonial powers, and indigenous traditions that have layered upon one another across centuries. The museum houses these threads together, from traditional Murut and Dusun cultural objects to the relics of wartime occupation and liberation.

Located in Mahathir Park, the museum has become one of the main tourism draws in Sabah's interior, a region that sees far fewer visitors than the coastal cities of Kota Kinabalu and Sandakan. Over 108,000 tourists visited Keningau between January and October 2018 alone, many drawn by the Oath Stone's relocation. The museum offers something rare in Malaysian tourism: a place where the story of nation-building is told not from the capital's perspective but from the interior, where the people who were asked to join a new country carved their conditions into river stone and have spent decades ensuring those promises are kept.