This species is known only from the vicinity of the type locality on the northern spurs of north-western Medellin, in Antioquia Department, Colombia, at 450m asl. It is most likely a more widespread species, but further survey work is needed.
Habitat and Ecology
This species has been found in vegetation along streams, but it has not been recorded outside forest habitats. Its breeding habitats are unknown but the larvae are most likely to develop in streams, as with other species of the genus.
It is considered to be quite rare, and it has not been recorded since 1988.
This species' habitat is threatened by habitat fragmentation, water pollution from mining, and infrastructure development for mining. It appears to be a lowland species, and might therefore be less at risk from chytridiomycosis than some other Atelopus species.
Even though it is a lowland species its potential susceptibility to chytridiomycosis should be investigated as part of its conservation measures, especially in view of the lack of recent records.
Wilmar Bolívar, John Lynch 2004. Atelopus sanjosei. In: IUCN 2014