Where can I get clay dirt to line a large pond?

[jaydon44]

Hey guys, just bought an acreage near Lethbridge

We want to dig a large pond for dogs to keep cool and for swimming.....and wayyy down the line stock some trout. hoping for about 50x100ft still thinking about depth...maybe 15 ft

My main question is where can a guy get clay near lethbridge to line the pond with...i might not need it depending on what i find when i start digging but a quick search on the net shows the closest place advertising clay fill was edmonton :S