Length 2 1/2 – 4 1/2 in. (6.5-11.5 cm). Northern Dusky Salamanders can be easily recognized by the light- colored line which extends from the back corner of the eye diagonally downward to the back corner of the mouth, and by the hind legs which are conspicuously larger than the front. Otherwise, coloration and body markings are extremely variable. Northern Dusky Salamanders may be found under rocks and similar debris in shallow woodland brooks, springs, and seepage areas in all but the northwestern quarter of Ohio. The most abundant and easily found of all our native salamanders, they are also one of the most difficult to catch. Northern Dusky Salamanders are alert, slippery, run swiftly, and are surprisingly good jumpers. Members of this family differ from all other salamanders in having an immovable lower jaw. The dusky must lift its head in order to open its mouth.
Text courtesy of the Ohio Division of Wildlife: https://wildlife.ohiodnr.gov/portals/wildlife/pdfs/publications/id%20guides/pub348.pdf