Where possible, the routing product defines a subbasin outlet as a Water Survey of Canada (WSC) or United States Geological Survey (USGS) flow gauge. In total, 53.5% of the WSC and USGS gauges are included in the routing product and so you will not find each and every WSC/USGS gauge on this map.
Search for gauge IDs in the top right corner and click on the markers on the map for more details about the gauges and the corresponding product to download if you want to study the watershed upstream of the respective flow gauge.