Rank MethodExpertise without calculation
Review Date2011-10-25
Change Date1996-09-18
Edition Date2011-10-25
Edition AuthorsHammerson, G.
Range Extent200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)
Number of Occurrences81 to >300
Range Extent CommentsRange includes the Mississippi River basin from Pennsylvania to Montana, and south to Louisiana; Gulf drainages from Mississippi River to Rio Grande drainage, Texas and New Mexico; and southward in additional drainages in Mexico (Page and Burr 2011).