This shrew is known from the Sierra Madre highlands of western Guatemala. It has gray fur and was recorded in cloud forest with deep leaf litter and moss.
The dorsal fur is light gray, the underside is only slightly paler, and the tail is uniformly deep gray.
Female Sorex madrensis have been found nursing young in July in Quetzaltenango, Guatemala. Reproductive condition recorded in the females provides a glimpse of nursing in the highlands.
The 2017 description reported that four of eight females collected there in July were lactating. Four females collected in January in Sacatepéquez showed no evidence of reproduction. The records preserve both the month and place in which reproductive condition was observed.
These animals had previously been grouped within Sorex veraepacis. Detailed comparisons of skulls and jaws distinguished the Sierra Madre population as this species. Re-examining the identity of specimens also linked their original reproductive records to the newly recognized shrew.
An extinction-risk assessment has not been added yet.
Retaining forest is a conservation concern in Cabricán, where the name-bearing specimen was collected. A municipal development plan prepared in 2010 described pressure on forest from timber and fuel extraction. Protecting mountain forest and monitoring both habitat and shrew occurrence would support conservation.