You can keep wild captured Tiger Salamanders in Alberta. They are listed as a non - licence Animal under the Wildlife Act. We also have Long Toed Salamanders in Alberta, and it is NOT legal to keep them. Make sure you have a tiger. Where on the Oldman did you find it, that would likely answer the question of species.
Tiger-
http://www.srd.alberta.ca/BiodiversityStewardship/WildSpecies/Amphibians/Salamanders/TigerSalamander.aspxLong toed-
http://www.srd.alberta.ca/BiodiversityStewardship/WildSpecies/Amphibians/Salamanders/LongtoedSalamander.aspxI used to raise and release tiger salamanders every year as a kid. I caught them as tadpoles, and would release them late in summer. I often kept a couple over the winter.
They are easy to keep healthy. Feed worms and waterbugs (leeches, dragonfly nymphs...) For your and the kids safety, and for the salamander. wash your hands and rinse well before and after handling it. Don't handle it too much....
In the Aquarium, I made it so there was an area with full water that sloped up to an area with land. Place a sloping rock or log on one side of the tank and place lots moss on it. Basically make a shoreline. I would use several inches of moss so the guys could crawl under it.
Tiger salamanders can live a long time, and grow quite large. It could be a pet for years. Releasing it after a while is a good way to educate the kids. Give them some time with it, with the knowledge it will be released. Later in life the process will be very meaningfull to them.
Enjoy!