Montana has about 9 to 10 species of spiders belonging to a host of different families. Of the poisonous spiders, the black widow is common, though another deadly species, the brown recluse does not thrive here. Certain house spiders of the wolf and jumping family are also indigenous to Montana.
Common spiders: Banded Garden (Argiope trifasciata), Platycryptus californicus
Largest spider: Hobo (Eratigena agrestis)