The species is known from 25 locations in Canada, where only a couple maternity colonies have been identified (COSEWIC 2003). The only known hibernacula in British Columbia are on northern Vancouver Island where M. keenii has been found in 8 caves from 3 separate areas (COSEWIC 2003). The species is known from just a few locations in southeast Alaska.

The distributional range suggests an association with coastal forest habitat (van Zyll de Jong 1985, Nagorsen and Brigham, unpubl. manuscript). Apparently this bat is associated with mature forests, but it is not restricted to old growth (COSEWIC 2003). Across the range it has been found roosting in southwest-facing rock crevices, among geothermally heated rocks, in tree cavities, in bark crevices, and in buildings (D. Burles pers. comm., Nagorsen and Brigham 1993, Parker and Cook 1996). Tree cavities and loose bark are important natural roost sites and may be limiting in some parts of the range (British Columbia Ministry of Water, Land and Air Protection 2004). In British Columbia, one maternity colony (on Hot Springs Island in the Queen Charlotte Islands) is situated within geothermally heated rocks associated with hot spring activity (British Columbia Ministry of Water, Land and Air Protection 2004). The only other known maternity colony in British Columbia was suspected to be in a tree located in a low elevation, southwest-facing cliff at Knoll Hill near Tahsis, Vancouver Island (COSEWIC 2003). Known maternity roosts and summer feeding areas in British Columbia are at elevations below 240 meters, known hibernation sites occur above 400 meters in caves over 100 meters long (British Columbia Ministry of Water, Land and Air Protection 2004). These bats have been observed foraging over hot spring pools and clearings above scrubby salal (Gaultheria shallon).

The range includes coastal Washington, British Columbia (including Vancouver Island, the Queen Charlotte Islands, and coastal mainland), and southeastern Alaska (e.g., Hoonah, Wrangell, Ketchikan) (Parker and Cook 1996, Simmons 2005). This species has one of the smallest distributional ranges of any North American bat (Van Zyll de Jong 1985).

A maternity colony in British Columbia is protected within Gwaii Haanas National Park Reserve. Weymer Cave and White Ridge Provincial Parks protect areas that support M. keenii hibernacula and roosting habitat. The former park has a draft management plan that identifies the need to protect the bat roosts, but also identifies recreational caving, hiking, and tourism as acceptable park activities (COSEWIC 2003).

Range-wide population surveys are needed. Coordinated surveys should be conducted in Alaska, British Columbia, and Washington. See British Columbia Ministry of Water, Land and Air Protection (2004) for specific protection needs and management recommendations.

This species is known only from a limited number of museum specimens. Virtually nothing is known about its biology (van Zyll de Jong 1985). Present research needs include the following: 1. Assess habitat preferences, including roosting and feeding areas, activity patterns, and food requirements. 2. Determine if there is any seasonal movement within the population. 3. Assessing whether this species hibernates, and if so, where and under what conditions. 4. Research the reproductive capacity of the species and evaluate its long-term population viability.