Suggested citation and version history for Topping, David J., Rubin, David M., and Schmidt, John C., 2008, Update on regulation of sand transport in the Colorado River by changes in the surface grain size of eddy sandbars over multiyear timescales: U.S. Geological Survey Scientific Investigations Report 2008-5042, 24 p. [http://pubs.usgs.gov/sir/2008/5042/]. Version 1.0, April 29, 2008 Initial release online at http://pubs.usgs.gov/sir/2008/5042/