The red-belled newt (Taricha rivularis) is a poorly studied endemic California salamander species that can be commonly found along the coastal forests north of Sonoma County. In 2009, a disjunct population of red-bellied newt was discovered 130 km south of its previously known range. Here we document the range and breeding phenology of this population as of 2019 and contrast its habitat use with that of other sympatric newts. Surveys across two years suggest that the southern population of T. rivularis is confined to one 1-km reach of Stevens Creek and a tributary informally called Twitty Creek, and the population follows an early-March to late-April migratory breeding pattern. Spatial analysis shows that breeding male T. rivularis aggregate only in Stevens Creek, likely dispersing through Twitty Creek, and that they associate with riffle and run mesohabitats rather than pools. Sympatric T. granulosa and T. torosa populations tended to associate more with woody debris cover types and cobble substrates than T. rivularis. T. rivularis oviposition site selection was most influenced by large substrate size. Protecting large substrate and complex instream habitat in sensitive breeding reaches, as well as upland habitat along dispersal routes, should be an important consideration for land managers. Understanding the nuances of range, temporal behavior, and habitat needs for this disjunct population is critical to ensure the survival of this California Species of Special Concern.