Cadomin Cave, Limestone cave in Whitehorse Wildland Provincial Park, Canada

Cadomin Cave is a natural limestone cave formed in the thickly bedded Palliser Formation of Leyland Mountain, at 1890 metres elevation. It has one known entrance and an upper series of spacious phreatic and keyhole-type passages, underlain by smaller passages linked by tight crawlways. The principal chamber of the upper series is the Mess Hall; the surveyed system measures 2,791 metres in length and 220 metres in depth.

The first formal survey of the system took place in 1959, leading to mapping of the upper passages and the central chamber. Scientists later expanded the known sections after discovering additional passages that changed understanding of the entire structure.

The name Cadomin is a portmanteau of the Canada Dominion Mining company, the firm whose prospectors opened the Coal Branch district in the early 1900s. The cave was almost certainly known to native peoples before that. Today the Alberta Speleological Society, official steward since 1997, runs periodic garbage cleanups, graffiti removal and bat counts.

Access to the system is currently not possible as the cave has been closed by government order since 2010 to protect bat populations. The closure prevents the spread of a fungal disease that threatens hibernating wildlife.

The cave is a hibernaculum for three bat species, chiefly little brown bats. A 2025 survey counted about 1,600 bats, consistent with records from the decade since a locked gate closed human access while still letting the bats pass.