The Hartmann’s mountain zebra are classified by taxonomists as a subspecies of the mountain zebra.
For me all zebras sort of look alike and at first I had a hard time figuring out if the Hartmann’s mountain zebra even looks different from the Grévy’s zebra I have posted about recently. But while Grévy’s zebras have dark brown stripes on a white background Hartmann’s mountain zebras have black looking stripes on a light brown background. Also Hartmann’s mountain zebras have a flap of skin on their chin and neck called a dewlap while Grévy’s zebras have a smooth neck. So they are definitely distinguishable even for people like myself who are relatively ignorant about zebra taxonomy.
Mountain zebra on Wikipedia.
Mountain zebra (Equus zebra) on ARKIVE.