Creator
- Environmental Systems Research Institute (Redlands, Calif.)6
- Geological Survey (U.S.)4
- United States. Bureau of Transportation Statistics2
- Firestine, Theresa1
- Hudgins, Andrew1
- Institute for Water Resources (U.S.). Navigation Data Center1
- U.S. Census Bureau. Geography Division1
- United States Geological Survey1
- United States. Bureau of Transportation Statisticsf1
- United States. Federal Transit Administration1
- Waterborne Commerce Statistics Center (U.S.)1