Actually the exact opposite is true. The CDN$ historically has traded below par. As recently as 2001 the CDN$ traded as low as 66 cents US.
Led by a right-of-center government Canada has outperformed those (other) economies over the past several years and its sound approach has been appreciated by voters who recently reelected the Conservatives. The market now appears to be signaling its satisfaction with the Conservatives as well.
Maybe. But, on a more basic level Canada has plentiful domestic energy and agricultural resources. In other words we can feed ourselves, run our industries, heat our homes, and drive our cars without relying on foreign suppliers. A relatively low corporate tax rate might also have something to do with it.