Barry Mitchell's Alberta Fishing Guide lists Rainbows and Cutts in Rockbound Lake. No mention of Tower, but that doesn't mean there isn't anything there.
Remember, you must purchase a NATIONAL PARKS LICENSE prior to fishing this lake. It's a completely different license from the Alberta sportfishing license and can be purchased in Banff at the Parks information centre.
Also, I looked up the regulations and I believe both Rockbound and Tower are CLOSED right now.
Check this link for more information:
http://www.pc.gc.ca/pn-np/ab/banff/visit/visit14a.aspx