Populations of a moderately thermophilic magnetotactic bacterium were discovered in Great Boiling Springs, Nevada, ranging from 32 to 63°C. Cells were small, Gram-negative, vibrioid to helicoid in morphology, and biomineralized a chain of bullet-shaped magnetite magnetosomes. Phylogenetically, based on 16S rRNA gene sequencing, the organism belongs to the phylum Nitrospirae.