Radio telemetry was used to determine spawning locations of wild adult summer run steelhead in the Zymoetz River. Conventional angling methods were used to capture adult steelhead in the river during the Spring, prior to spawning. Radio transmitters were inserted into the stomachs of fourteen fish. These steelhead were tracked by helicopter on six separate flights over a two month period. It was determined that ten of fourteen steelhead utilized the upper 20 km of the Zymoetz River, however, only two of those spawned at the outlet of McDonell Lake. The importance of a number of smaller systems in the upper Zymoetz watershed is discussed as is the need for a regulation change to protect overwintering summer steelhead.