These trends include all counts of fish obtained at trap or ladder facilities in dams or other similar permanent fish barriers, and at all weirs that are not located at a hatchery or satellite facility. Methods may include dam, weir, or sonar, and count types are either total live fish or peak / index live fish. Life stage may be adults, jacks, or a combination of the two life stages, and is presumed to be adults, unless specified otherwise in the source documentation. The principal source for mainstem Columbia River dam counts is the data base maintained by the Columbia River Intertribal Fish Commission; sources for other data are published agency reports, and unpublished agency files and data bases. More technical information is available for this data category's database structure.