I just purchased the Leuold 4.5X14 with the varmint reticule.
"this mark and the 500yd mark is equal to the height of a Pairie Dog at 300yds"

Absolutly wonderful, except I have never seen a Pairie Dog!
How tall do they stand?

Probably the logical thing would be to mark a pole 12" and take sightings at different distances.

Your stated one foot high will do the trick. That's the average size of a standing prairie dog.

Thanks.
Perhaps I should point out to Leupold that probably 75% of the civilized world has never laid eyes on one of the lil' critters!