Deep in the South Appalachians, the Northern Flying Squirrel lives in spruce fir and northern hardwood forests. Some Northern Flying Squirrels have been captured in stands of varying age, understory density, and composition. Smyth, Grayson, and Highland. Northern Flying Squirrels probably mate when they are one year old, although this has not been confirmed. The gestation period runs from 37 to 42 days.
Females typically have one, or possibly two, litters of one to six young per year.
The females nurse their young for approximately two months. The Northern Flying Squirrel does not have many enemies. The limited and discontinuous range of this species in the southern Appalachians makes it vulnerable to a number of both natural and human-related impacts. Even without human intervention, small, relict populations might suffer disproportionately from genetic constraints as well as from climatic and vegetational processes associated with post-Wisconsin changes in mountain environments. In 1985 when the subspecies was listed, there were only 10 documented captures of this squirrel in West Virginia.