The Brao-Kavet are an indigenous ethnic group in northeastern Cambodia and southern Laos. Although in recent decades most have been forced to resettle in the lowlands, many maintain close livelihood and spiritual links with forested mountainous areas. I discuss the shifting Brao-Kavet understandings and performances associated with sacred spaces and, in particular, the Haling-Halang, a pair of high mountains located on the Laos-Cambodia border. The Brao-Kavet do not hunt for wildlife on these mountains, and dare not cut down trees. A particular kind of thin bamboo that grows there is, however, especially useful for sucking jar beer. People are allowed to harvest it in small quantities, provided appropriate offerings are made to the powerful mountain spirits prior to cutting. Brao-Kavet identity politics are closely linked to religious practices associated with these mountains, as demonstrated by Brao-Kavet claims that only Brao-Kavet should be spoken there because the spirits do not understand Lao, Khmer, French, English, or other languages, and would be offended if anything but their own tongue was uttered. I argue that the performative nature of Brao-Kavet sacred mountains has considerable political potential for facilitating indigenous supported biodiversity conservation, and for supporting the recognition of Brao-Kavet indigenous rights over land and other resources in Virachey National Park, where the mountains are located.