Resource Trend Analysis water quality and sediment sampling in Upper Mississippi River Pool 13, was initiated in August 1988 as a part of the Long Term Resource Monitoring Program. Mississippi Monitoring Station personnel began water quality sampling on Pool 13 the first week of August using equipment and techniques based on the Procedures Manual for the Long Term Resource Monitoring Program. Over 2600 water quality measurements were made under the Resource Trend Analysis component of the Long Term Resource Monitoring Program on Pool 13 during the sampling period, August 1, 1988 through October 31, 1988. Dissolved oxygen increased throughout the sampling period. Means at channel habitats were slightly higher than backwater means. Specific conductivity increased similarly in all habitats throughout the sampling period. Nephelometric turbidity means displayed a close association with secchi disk transparency means, each displaying fluctuation during the sampling period. Mean turbidities were higher in backwater habitats than channel habitats and mean secchi disk values were lower in backwater habitats than channel habitats. Velocity means were variable throughout the sampling period, fluctuating with the mean flow through the lock and dam.