The distribution of this species currently includes Gunung Kinabalu and Tawau Hills National Park (Sabah). The altitudinal range possibly extends from 550 to above 1600 m a.s.l. Type locality is Gunung Kinabalu, Silau-Silau. At Tawau Hills it can be found together with L. phylax, however with the latter species populating lower elevations.

Despite being a relatively small frog in general, it is relatively large within the palavanensis-species groupf of Guardian Frogs, with adult males measuring approximately 29–32 mm in snout–vent length and adult females measuring 32–38 mm.

According to the original publication, the Mountain Guardian Frog shares several features with other Guardian Frogs of the palavanensis-species group: a finely shagreened dorsum, marked by prominent longitudinal dorsolateral glandular ridges. The interorbital distance is equal to or greater than the width of the upper eyelid. Its toes are not fully webbed, and a distinctive horseshoe-shaped dermal ridge is present in the middle of the back, just behind the level where the arms are inserted. 

This species is distinguished from all other members of the palavanensis-species group by the a combination of  features. These include reduced toe webbing and a subangular supratympanic fold, with the anterior and posterior parts approximately equal in length. A clearly visible pineal spot is located at the level of the anterior edge of the upper eyelid. The vomerine ridges are short and very widely spaced. A low, glandular, and moderately distinct median ridge extends from the horseshoe-shaped ridge to the cloaca, while postpalpebral and lumbar ridges are absent.

Little is know about the species' natural history. As other Guardina Frog species, it lives in the moist leaf litter in primary rainforest. It deposits its eggs in the leaf litter. The clutch is guarded by the male. Once tadpoles hatch, tadpoles climb on the back of the male which transports them to a nearby body of stagnant water. The tadpoles are similar in size, body contour, color pattern and tail fin shape to other Guardian Frog species; distinguishing characters have not been worked out yet. 

The advertisement call of the species is unkown.