[2] The Cornell Lab of Ornithology's Birds of the World lists three subspecies, but notes that this treatment is disputed and that timberline wren should be "perhaps better considered monotypic.

It has a broad gray-white supercilium, a chocolate brown stripe behind the eye, and grayish cheeks with narrow black markings.

T. b. basultoi has a wider supercilium, whitish markings on the upperparts and the sides of its neck, and has whiter underparts.

[3] The timberline wren's range is disjunct, and spans from central Costa Rica south to northern Panama.

[3][4] The timberline wren inhabits páramo and near-páramo moorland at the upper edge of tree line, and is partial to bamboo thickets.

[3] The timberline wren typically forages on or near the ground, sometimes fluttering to pick prey from leaves and creeping along mossy branches.