Oklahoma Territorial Plaza Adventure Lab Bonus Mystery Cache

The bonus cache is not located at the posted coordinates
but it is within 2 miles.

This is the bonus cache to the "Oklahoma Territorial Plaza" Adventure Lab. 

In order to find and log this Bonus Cache
you must first complete the 5 Adventure Lab caches
and determine the code word for the checker.

Using the first character (either letter or number) from each Lab location answer enter them in alphabetical then numerical order into the checkler for the Bonus cache coordinates.  

You can validate your puzzle solution with certitude.