Mountain meadows inhabited by beavers have an important role in mitigating climate change. As carbon sinks, they store remarkably large amounts of greenhouse gases for the long term. However, degradation from livestock grazing and conversion to dry grasslands has greatly diminished the carbon-storing capacity and biodiversity of meadows in the Cascade Range and Sierra Nevada of California. Restoration of these biodiversity hotspots is key for creating climate refugia for sensitive species and increasing carbon sequestration.