[2] This species is found in Canada (New Brunswick and Nova Scotia)[5] and northeastern United States (Connecticut, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Vermont, Virginia and West Virginia);[6] It was formerly found in Rhode Island and four watersheds in Massachusetts but are now extinct in Rhode Island and almost extinct in Massachusetts.

[2] 1897 Research by Arnold Edward Ortmann showed it to be common in the Delaware and Susquehanna Rivers.

[8] It associates with longnose and eastern blacknose dace, golden shiner, pumpkinseed, slimy sculpin and yellow perch.

[9] The brook floater is sensitive to habitat loss for development, dams and road crossings, pollution, summer droughts, trampling, sedimentation, flow alteration, and low oxygen conditions.

[12] While the IUCN lists it as Vulnerable, the states of New Jersey, Virginia, Massachusetts and New Hampshire[2] all list it as Endangered,[13] Threatened in Vermont, Maine and New York,[14] Rare/Endangered in Connecticut,[9] Extinct in Rhode Island and "Species of Special Concern" by the federal government.