A new cave population of sculpin fish from Central Pennsylvania is described that, if confirmed to be cave adapted, would become the second northernmost cave-adapted fish in the world. The Tytoona Cave fish lack the suite of modifications typical of troglomorphic populations. Their eyes, pectoral fins, and mouths appear to be as large as those of their surface counterparts, they have the same number of cephalic lateralis pores, and their pigmentation levels do not appear to be much lower. Nonetheless, they are considered to be cave adapted due to the presence of ovigerous females, a lack of evidence for starvation, and primarily because the cephalic lateralis pores (part of the lateral line system) are significantly larger than those of similar-sized surface fish. It may be that the Tytoona Cave population only has some emergent cave adaptations because in high latitudes the extent of polar ice sheet migration during the Pleistocene era restricted colonization by fish at least until 12 ka ago, when the ice age ended.