Porcupines are found in a variety of habitats including dense forests, tundra, grasslands and desert shrub communities. Like their distribution, their diet is also generalized, but shows a marked difference between winter and summer seasons. Winter foods are primarily the bark, cambium and phloem of trees. In the spring their diet shifts and porcupines begin feeding on roots, steams, leaves, berries, seeds and grasses. This species primarily is nocturnal and does not hibernate (Woods 1973). The average home range size was found to be 0.98- 0.33 km² at the 95% isopleth, 0.72- 0.25 km² at the 90% isopleth, and 0.25-0.07 km² at the 50% isopleth. and used only white spruce and paper birch trees for foraging in Alaska (Coltrane and Sinnott 2013). Predation increases during the winter when there is more precipitation (Mabille et al. 2010). In the winter the species survives based on adaptability of food intake, tolerance of low-quality diets and low ambient temperatures; they count on summer forages to replenish their fat and protein (Coltrane et al. 2011).

This species occurs in the southern half of Canada, and northern and western United States, as well as scattered populations throughout the eastern U.S; the northern boundary of Mexico from the lower-middle Baja Peninsula, east to the eastern border of mainland Mexico in a relatively straight line, but not in Baja or the Yucatan (Barthelmess 2016, Ceballos and Oliva 2005). There is a new record from the Sierra Juárez, municipality of Juárez, Chihuahua, Mexico (Gatica-Colima et al. 2014). There have also been records that their range extends into the Eastern Margin of the Edwards Plateau in Texas (Baird et al. 2009) and Webb County (Goetze and Miller 2012). Their range has also extended into northeastern Oklahoma (Caire et al. 2009).

North American porcupine habitat falls within several protected areas within Canada, the U.S., and Mexico which has allowed the species to reestablish its populations.