It is found only in a small region of the Andes in central Bolivia, where it lives in cloud forest at altitudes from 2600 to 3000 m.[3] Exceptionally small for its genus,[4] O. hucucha was first recognized as new when a specimen was caught in 1984 in the Siberia Cloud Forest in Bolivia's Cochabamba Department, near the border of Santa Cruz Department.

[5] Two other specimens caught nearby[6] in 1955 and 1979 were then recognized as pertaining to the same species; one had been misidentified as Akodon mimus.

[5] In 1987, O. hucucha and another small Oxymycterus, O. hiska from Peru, were named and described in an American Museum Novitates paper by Flavio Hinojosa, Sydney Anderson, and James Patton.

Furthermore, the skull is narrower, the palate is longer, and the upper incisors are oriented more to the front, among other differences.

[6] The IUCN lists its conservation status as "endangered" because it has a small distribution, its habitat is being destroyed, and it is not known from any protected areas.