The Meaning Behind Montana’s License Plate Numerical Prefixes

Many visitors to Montana question the numerical prefixes found on the state's license plates.

Not to mention the numerous varieties of plates, which at last check was at 238 different designs to choose from.

As drivers pass through various locations, they may notice changes in the plate numbers, raising questions about the meaning behind these numbers. Montana has mandated car registration plates since 1915; the state government first proposed a system to mark vehicles by county of registration in the 1930s.

For decades, people have held the view that the numerical codes derived from 1930 U.S. Census population statistics.

This method allocated lower numbers to counties with higher populations; Silver Bow County, having the highest population at the time, was coded as 1. Most Billings area standard blue plates begin with a 3 since Cascade and Yellowstone counties followed with codes 2 and 3, respectively.

If you'd like to play a fun game while in the treasure state, here is a list of all the numbers and corresponding counties:

On closer examination, the 1930 population ranks show differences between the allocated plate numbers and real census data. For instance, Powder River County, rated 46th in population in 1930, received the code 9. Gallatin County, which came in ninth in population, got the code 6. Historians have proposed several ideas of political influence, bribery, and even typographical mistakes to explain these discrepancies.

Notwithstanding these initiatives, no one theory explains why several counties got plate numbers that defied their population ranking. A legislative proposal meant for a system update surfaced in 1999.

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Using more recent data, the plan aimed to make the numbering system more relevant. It did not, however, attract support, probably because of worries about the uncertainty it would create among people used to the decades-old system.