http://www.srd.gov.ab.ca/lands/using...oundaries.aspx
Specifically: "The beds and shores of a river or stream that are bounded by private land may generally be traversed below the ordinary high water mark without fear of trespass."
The only clause you have to watch for is: "Undefined Stream Channels: Water features that that do not have a definable bed or channel are not owned by the Province." If that's the case I doubt there's any fish in that stream
