Fish and Wildlife Enforcement writes: These trout were seized from anglers on the Bow River. They are all over 35 cm, and according to the regulations, trout that size from the Bow River must be released. The rules may vary according to species of fish and section of the river. Some sections are even closed to fishing right now.
We encourage all anglers to check this page for the full breakdown, and know before you go: http://www.albertaregulations.ca/fishingregs/es1.html
H/T to Mike Kelly