The tortoise is a land-dwelling reptile that spends over 95% of its time in a burrow that it constructs with its shovel-like front feet (Morafka 1982).  Burrows have a single opening, are roughly 2.5 m deep and 10 m or more in length, and act as refugia from predators and temperature extremes (Morafka 1982).  While the closely related gopher tortoise (Gopherus polyphemus) uses several burrows in any given active season, Bolson tortoises show strong preference for a single burrow which they defend against potential intruders by blocking the entrance with their bodies (TESF unpublished observation).  Plant cover greatly influences burrow occupancy and creates a suitable micro-climate that could help determine appropriate repatriation sites (Becerra-Lopez et al. 2016).  Considering the very close relationship of the tortoise with its burrow we expect very high site fidelity for this species.  

The tortoises remain out of sight deep in their burrows while they brumate between November and March (TESF unpublished data).  All foraging, nesting, and mating activities take place during the tortoise active season from ~April to October (Legler and Vogt 2013).  

Adults may grow quite large up to 40 centimeters (15.75 inches) with fossil records of carapace lengths measuring more than 1 meter (39 inches) (Swingland and Klemens 1989; Service 1978b).  However, the largest known contemporary individuals are much smaller than this and rarely exceed 390 mm (15.35 inches) in shell length (Legler and Vogt 2013; TESF unpublished data).  Adult males are generally smaller than females in this species and show few (if any) morphological features prominent in other male chelonians, such as concave plastron, prominent chin glands, extended gular projection, distinct eye color, or larger, thicker tail with a more distal cloacal opening, to clearly distinguish them from females (Morafka 1982). 

The average lifespan of a Bolson tortoise is not known, but probably lies upwards of a century. 

Bolson tortoise courting and mating behaviors begin in late spring and continue through the fall (Legler and Vogt 2013, TESF unpublished data).  Nesting takes place the following year starting in late April or early May and generally commences in mid-July.  Most female tortoises will lay two clutches per year (range: zero to three), with an average of 5-6 eggs per clutch (Morafka 1982, TESF unpublished data).  Nests are dug with the hind legs and are thus typically shallow.  How tortoises select nest sites is currently unknown.  Approximately half of the nests are in or near a burrow (which may or may not be the burrow occupied by the nest-maker), but nest sites under shrubs or other vegetation far from the nearest burrow are equally as common.  Hatchlings emerge from the egg after 75-120 days of development.  Hatching starts in July or August and ends in October (Morafka 1982, Legler and Vogt 2013).  Depending on the exact date of hatching, neonate tortoises may have the opportunity to forage only for several days or weeks before the onset of cooler temperatures compels them to seek shelter and brumate for the colder months, most often in a rodent burrow.  Hatchlings will also occasionally forgo foraging by remaining in the nest and only emerging the following spring or summer (Legler and Vogt 2013, TESF unpublished data).  A combination of low metabolic rates and ample yolk provisions by the mother (the only form of parental care enjoyed by hatchling tortoises) allows them to do so.

This species at present is restricted to a relatively small area of the grasslands of north-central Mexico in the states of Chihuahua, Coahuila, and Durango (Service 1978) where it exists in disjunct sub-populations.  The Bolson tortoise once had a much larger range that included much of the southwestern United States.  Fossil records indicate that during the Pleistocene Epoch the tortoise was present in the southern Great Plains and northern Mexican Plateau extending from southwestern Arizona, Oklahoma, Trans-Pecos Texas, and the Mexican state of Aguascalientes during the Pleistocene (Auffenberg and Franz, 1978).  Post-Pleistocene, the Bolson tortoise continued to inhabit the southwestern U.S., likely including New Mexico, and likely overlapped with Native American occupation of this area (Morafka 1982).  Its current distribution thus represents a contraction of its range of >90% (Morafka et al 1989).  Population declines are not a thing of the past and tortoise numbers continue to dwindle in Mexico - mainly due to human predation and activities - such that the current wild population is estimated to consist of fewer than 2,500 adults (Kiester et al., 2018). 

While Bolson tortoises are herbivores that favor tobosa grass (Hilaria mutica), they are opportunistic grazers that will include other available grasses and herbaceous annuals in their diets (Morafka 1982).