Breeding occurs generally in winter or spring (sometimes in summer), with the earliest breeding occurring in lowland areas in the southern part of the range: mid-May to early August in northern California, January-June in southern California, late April-early May in northern Idaho. Eggs are laid in packets of about 20-80, hatch in 3-5 weeks in western Oregon. Larvae metamorphose into tiny frogs within about 2-3 months. In northern Idaho, metamorphosis occurred in mid- to late summer (Schaub and Larsen 1978). Most breeders are at least 2 years old, but some individuals may mature in less than 1 year in western Oregon (Nussbaum et al. 1983). Multiple clutches per year have been documented in southern California (Perrill and Daniel 1983).
Calling frequently occurs outside the breeding season and far away from breeding sites.