A standard 52-card deck.
Build all four suits up from ace to king in separate piles.
Shuffle the deck.
Deal out 28 cards into seven piles, in the following manner: The first pile (left to right) includes one card, the second pile includes two cards, the third pile includes three cards, etc., so that the last pile has seven cards. This array is known as the tableau.
Turn the top card on each pile face up, so that there are 7 face-up cards.
The remaining 24 cards should be dealt evenly on top of the six piles other than the one with the single card; these cards are placed face up and overlapped so that all of the face-up cards can be seen.
See Yukon Solitaire - Illustrated Setup for an example.
As they become available, the four Aces must be played above the tableau; these are the four foundations. Cards of the same suit may be played on each Ace in ascending order, from low (2) to high (King).
Only cards which are completely uncovered may be played on a foundation.
Once a card is played on a foundation, it can't be removed.
Playing on the Tableau
The next-lowest card of the opposite color may be added to the top of a tableau pile (i.e., black on red, or red on black). EXAMPLES: The Jack of spades can be added to the Queen of hearts, or the 4 of diamonds could be added to the 5 of clubs.
Any card in the tableau may be moved in this manner; all cards on top of it are also moved.
EXAMPLE: In this photo, the 8 of hearts in the far right column can be played on top of the 9 of spades in the third column from the left. If a player chooses to do this, the 10 of clubs and 6 of diamonds are moved with the 8 of hearts and retain their respective positions.
When a face-down card is uncovered, turn it face up. It then becomes available to be played or to be played on.
NOTE: No card may ever be added to an A in the tableau. As each Ace is revealed, it must be played above the tableau as a foundation.
If a column in the tableau is emptied, any visible King (or a visible King with other cards on top of it) can be moved to fill that space.
You win Yukon Solitaire by building all four suits up from Ace to King.