Such areas must include a water source. North and east slopes, often at the base of cliffs or rockpiles, appear to be favored. Preferred rocky areas are often over decomposed granite soils, which are moistened by seeps or melting snow. Individuals are nocturnal during the period of surface activity and are most likely to be encountered on the surface during or after rains. Individuals occupy surface microhabitats during periods of surface moisture in the spring, summer, and fall but retreat to moist subsurface refugia during dry periods and winter.
Most individuals probably move much shorter distances.
It is possible that oviposition occurs during the fall with hatching occurring in the spring or early summer. Because of their secretive habits and the relative absence of potential predators in the habitats where they normally occur, this species is probably not taken in large numbers as prey by any vertebrate species. No other salamander normally occurs in the preferred habitat of this species. The natural history and classification of the Mount Lyell salamander, Hydromantes platycephalus. Gorman, J. 1956.