The Grand Canyon expansion for Canyon consists of eight special cards that change the normal flow of the game, six floating obstacle tiles to place on the board, and six special rapids tiles to create a unique waterfall.

The Cards
Changing Horse: May discard two cards before the start of a hand and draw two cards to replace them.
Crazy Color: May choose not to follow suit once in that hand.
Grüner Span: May hop over boats ahead of the player, Checkers-style.
Mad Move: May change the number of cards drawn for that hand.
Manitou: May discard another player’s Grand Canyon card, or may move 1-2 spaces on the board, whether or not the player makes his bid.
Pushing Bull: May push one canoe in player’s path one space in any direction.
White Wind: May miss player’s bid by one less and still receive the movement bonus.
Wooden Heart: May place the floating obstacle tiles on the board after everyone else has chosen a Grand Canyon card.