The Disney official history goes like this:  Hidden Mickeys started in the late 1980's in Epcot as an inside joke among the Imagineers.  Hiding Mickey around WDW was just plain fun!  However, Jim Hill (jimhillmedia.com) believes in this "unofficial history":  Hidden Mickeys were born as the Imagineers were designing Epcot in the late 1970's and early 1980's.  At that time, Disney management felt that the characters belonged in the Hollywood Studios only.  The Imagineers disagreed and began slipping Mickeys into Epcot!  I suspect that Mickey Mouse designs that were previously in place in WDW (and Disneyland) also became known as Hidden Mickeys.  Because of the popularity of HM's, Imagineers are encouraged to place them in new construction.

What Are Hidden Mickeys????
A Hidden Mickey (HM) can take different forms.  The most common image is the tri-circle Mickey frontal silhouette:  three circles that form Mickey's round head and adjoining round ears.  Other images include a side or oblique (usually three-quarter) profile of Mickey's face and head, a side profile of his entire body, a full-body frontal silhouette, a detailed picture of his face or body, or a three-dimensional Mickey.  Sometimes, just his gloves, handprints, shoes or ears appear.  Even his name or initials in unusual places may qualify as Hidden Mickeys.  And don't forget other characters:  Hidden Minnie Mouse, Donald Duck, Goofy, Pooh, Chip-n-Dale etc.

Most debate about HM's involves the classic three-circle forms.  My definition of a "true" three-circle HM is rather strict:  the circles must touch and be in the right position and proportions.  However, there are distorted three-circle Mickeys that are not positioned or proportioned correctly but are so accepted among cast members and the public that I include them as HM's; for example, the HM gear wheels on the ground to the right near the end of the Big Thunder Mountain Railroad track in the Hollywood Studios and the various lock HM's, such as the lock on the jail cell door near the end of the Pirates of the Caribbean boat ride.  Neither of the above HM's is proportioned quite right.

HM's are added during some rehabs (like when the high-tech living room and kitchen were added, along with some HM's, to the Carousel of Progress attraction in the Hollywood Studios).  HM's are also lost during rehabs; for instance, three HM's disappeared from Old Port Royale in the Caribbean Beach Resort when the food court area was remodeled.

Scavenger Hunting for Hidden Mickeys
To have the most fun and find the most Mickeys, follow these tips.
Arrive early at the theme park for the hunt; say 30 minutes before the official opening time.  Pick up a Guidemap and plot your course.  Than look for Hidden Mickeys in the waiting area while you wait for the rope to drop.  You'll find the clues for those areas by checking the Index to Mickey's Hiding Places in the back of the Hidden Mickeys book.  Look under 'Entrance areas." If you arrive later in the day, you may want to pick up a FASTPASS for the first attraction and then skip down a few clues to beat the crowds.

Scoring
All Hidden Mickeys are fun to find, but all HM's aren't the same.  Some are easier to find than others.  I have assign point values to HM's, identifying them as easy to spot (Value of 1 point) to difficult to find the first time (5 Points).  I also consider the complexity and uniqueness of the image:  the more complex or unique the HM, the higher the point value.  For example, the easy-to-spot HMs in Mickey's Toontown Fair in Hollywood Studios is scored at one-point.

Clues from the Book
There are 28 locations containing over 74 Hidden Mickey's currently found in the Epcot theme park.

USA Pavilion!
Clue:  Take a good long look at the bronze eagle reliefs.
2 Points for each floor:
Maelstrom in the Norway Pavilion
Clue:  Find the Viking wearing the Mickey ears.
3 Points
Mission Space Pavilion
Clue:  You must ride the attraction to spot the first Hidden Mickey.
4 Points

To learn more about what does and does not qualify as a Hidden Mickey visit
Author:  Steven M.  Barrett       http://www.hiddenmickeysguide.com