The Cow Branch Formation is a Late Triassic rock unit in the Dan River-Danville Basin of Virginia and North Carolina, best known for dark lake-laid mudstone and shale deposited in repeated cycles. Lying between the Dry Fork and Stoneville formations, it is most famously exposed at Solite Quarry near Eden, where exceptionally preserved fossils were first reported in 1978. These rocks record a warm tropical lake system near the equator, with cycles of deeper and shallower water likely tied to long-term climate variation. Especially important as a konservat-lagerstätte, the formation preserves insects, fish, small reptiles, plants, and dinosaur tracks in remarkable detail.