The location of release site, just below Bonneville Dam, and detection array locations are in the green circles. Note the River location is at about RM90, the Estuary location is near the head of the estuary about RM25, and the Ocean location is near the mouth of the Columbia. Travel times and survival estimates were calculated from the release site to each detection site. Survival was estimated using a maximum likelihood estimator that takes detection probability into account to estimate survival. Release dates ranged from late April through July 1. A total of 10 releases were made over the three years.