Below is a working checklist of Mount Desert Island's mammals. For more information about a particular species, click on the link under the heading "common name".
Please send corrections and updates to info@vfthomas.com. Photographs are welcome. Thank you.
| Order | Family | Genus | Specific Epithet | authority | common name | Sources (full citations given after this table) |
| Lagomorpha | Leporidae | Lepus | americanus | Erxleben | Snowshoe Hare | ANP |
| Rodentia | Muridae | Clethrionomys | gapperi | (Vigors) | Southern Red-backed Vole | ANP |
| Rodentia | Muridae | Peromyscus | leucopus | (Rafinesque) | White-footed Mouse | ANP |
| Rodentia | Muridae | Peromyscus | maniculatus | (Wagner) | Deer Mouse | ANP |
| Rodentia | Muridae | Rattus | norvegicus | (Berkenhout) | Norway Rat | ANP |
| Rodentia | Muridae | Synaptomys | cooperi | Baird | Southern Bog Lemming | ANP |
| Rodentia | Dipodidae | Napaeozapus | insignis | (Miller) | Woodland Jumping Mouse | ANP |
| Rodentia | Dipodidae | Zapus | hudsonius | (Zimmermann) | Meadow Jumping Mouse | ANP |
| Rodentia | Castoridae | Castor | canadensis | Kuhl | American Beaver | ANP |
| Rodentia | Sciuridae | Glaucomys | sabrinus | (Shaw) | Northern Flying Squirrel | ANP |
| Rodentia | Sciuridae | Glaucomys | volans | (L.) | Southern Flying Squirrel | ANP |
| Rodentia | Sciuridae | Marmota | monax | (L.) | Woodchuck | ANP |
| Rodentia | Sciuridae | Sciurus | carolinensis | Gmelin | Eastern Gray Squirrel | Champlainers (TFV, EMW, PKW); ANP |
| Rodentia | Sciuridae | Tamias | striatus | (L.) | Eastern Chipmunk | ANP |
| Rodentia | Sciuridae | Tamiasciurus | hudsonicus | (Erxleben) | Red Squirrel | Champlainer (TFV); ANP |
| Rodentia | Erethizontidae | Erethizon | dorsatum | (L.) | Common Porcupine | Champlainer (TFV); ANP |
| Insectivora | Soricidae | Blarina | brevicauda | (Say) | Northern Short-tailed Shrew | ANP |
| Insectivora | Soricidae | Sorex | cinereus | Kerr | Masked Shrew | ANP |
| Insectivora | Soricidae | Sorex | fumeus | G. M. Miller | Smoky Shrew | ANP |
| Insectivora | Soricidae | Sorex | palustris | Richardson | American Water Shrew | ANP |
| Insectivora | Talpidae | Condylura | cristata | (L.) | Star-nosed Mole | Champlainer (EMW); ANP |
| Insectivora | Talpidae | Parascalops | breweri | (Bachman) | Hairy-tailed Mole | ANP |
| Carnivora | Canidae | Canis | latrans | Say | Coyote | ANP |
| Carnivora | Canidae | Vulpes | vulpes | (L.) | Red Fox | Champlainers (RGG, TFV, EMW); ANP |
| Carnivora | Mephitidae | Mephitis | mephitis | (Schreber) | Striped Skunk | Champlainer (RGG) |
| Carnivora | Ursidae | Ursus | americanus | Pallas | Black Bear | ANP |
| Carnivora | Mustelidae | Lutra | canadensis | (Schreber) | River Otter | Champlainers (DL, TFV); ANP |
| Carnivora | Mustelidae | Martes | pennanti | (Erxleben) | Fisher | ANP |
| Carnivora | Mustelidae | Mustela | erminea | L. | Short-tailed Weasel | ANP |
| Carnivora | Mustelidae | Mustela | frenata | Lichtenstein | Long-tailed Weasel | ANP |
| Carnivora | Mustelidae | Neovison | vison | (Schreber) | Mink | ANP |
| Carnivora | Procyonidae | Procyon | lotor | (L.) | Common Raccoon | Champlainer (TFV); ANP |
| Carnivora | Phocidae | Halichoerus | grypus | (Fabricius) | Gray Seal | ANP |
| Carnivora | Phocidae | Phoca | vitulina | L. | Harbor Seal | Champlainer (EMW); ANP |
| Chiroptera | Vespertilionidae | Eptesicus | fuscus | (Beauvois) | Big Brown Bat | ANP |
| Chiroptera | Vespertilionidae | Lasionycteris | noctivagans | (LeConte) | Silver-haired Bat | ANP |
| Chiroptera | Vespertilionidae | Lasiurus | borealis | (Müller) | Red Bat | ANP |
| Chiroptera | Vespertilionidae | Lasiurus | cinereus | (Beauvois) | Hoary Bat | ANP |
| Chiroptera | Vespertilionidae | Myotis | lucifugus | (LeConte) | Little Brown Bat | ANP |
| Chiroptera | Vespertilionidae | Myotis | keenii | (Merriam) | Northern Myotis | ANP |
| Primates | Hominidae | Homo | sapiens | L. | Modern Human | Champlainers (all) |
| Artiodactyla | Cervidae | Alces | Alces | (L.) | Moose | ANP |
| Artiodactyla | Cervidae | Odocoileus | virginianus | (Zimmermann) | White-tailed Deer | Champlainer (TFV); ANP |