January 25 - April 12, 2019*

Photoperiod Clues
Track day length to estimate latitude.

 January 25 - April 5
Time Clues
Investigate Universal Time to estimate longitude.
       March 8

Continent, Country, City Clues
Research facts to pinpoint locations.

March 15 - April 5
Mystery Sites Revealed
Mystery Class locations and challenge results
  April 12

* Please note: Due to budget limitations, our spring 2019 Mystery Class challenge will be a replay of a previous year's challenge. We will reveal the locations of the 10 Mystery sites on April 12th but will not be able to hold a year-end contest.