When my son turned nine, he had a birthday party. Four visiting boys made the perfect crew for a treasure hunt!

Readers of Cockeyed.com will remember all the other backyard buried treasure hunts I've set up over the years: (1, 2, 3, 4)

A vital part of the setup was revealing the combination to the final padlock. I printed out a photo of the correct combination and tore the photo into four long strips with each showing one number: 2, 0, 0 and 7. I reasoned that the boys would be able to open the lock even if they couldn't find all four numbers.

I have a medium-sized California backyard, so for the setup I bury a treasure chest, draw a map and hide clues all over the yard.

I buried the chest within this compost/grass pile against the back fence. Because I had buried the chest a few days early, the brown grass looked undisturbed on the day of the treasure hunt.

I launched the treasure hunt with a master clue sheet.

The doorbell rang and when the kids opened the door, they found this block of ice on the porch, with a mysterious note attached.

In minutes, they had smashed it against the driveway and recovered the clue sheet inside.

Around the edge of the clue sheet, twenty four words surrounded a skull and crossbones. These were the hints to find hidden envelopes.

For example, "310 red ones" was the hint for an envelope under a loose brick (our wall is made of 310 bricks total). "Oscar the Grouch" was the hint for a clue taped to the bottom of the garbage can.

This master clue sheet provided clues to ten hidden envelopes. Every boy could see the clues and try to solve them at the same time.

In my experience, if the party gets one clue at a time, one kid tends to monopolize the clues and gets first crack at all of the answers. That is a less-than-ideal situation. Everyone is happiest when they are an active participant, solving at least one clue and finding an envelope. It is super fun!

As the envelopes were discovered, new clues found their way to the picnic table.

A sketched map of the backyard caused a lot of debate. The trees looked like tables, and vice-versa.

A breakthrough was reached when the boys realized they needed to tape the map quarters together and re-orient it to match the layout of the yard.

My son had recently discovered a tree-branch path onto the roof, so I gave one clue which gave him an excuse to climb up there: SANTA DOOR

The completed map. When a new clue was new and vital, everyone wanted to look at it first.

A few clues, such as TREE TOP, were vague, launching an all-out tree borne hunt for a white envelope.

Finally, the map, the treasure coordinates and the lock combination came together and enabled the kids to start digging.

There was no X on the map this time, but instead the position was revealed with row and column names, like finding the submarine in a battleship game.

Probably the most dangerous part of the hunt is letting one boy wield a steel shovel while eight bare hands are clawing at the same spot.

They poked at two spots before zeroing in on the precisely correct digging spot. The dead grass pile was easy to dig through and soon they hit something solid.

A spray-painted tool chest held the treasure; the final obstacle was a brass padlock. Four voices shouted the number combination in unison: 2007!

The chest opened up and they rejoiced at their share of the booty! There were seven pairs of sunglasses and a bag of chewing gum!

It was a success! There were a dozen moments of confusion and many perplexed faces, but they puzzled through all of the questions and got to the end triumphant.

Congratulations boys!