The store opened a few months after Washington voters passed Initiative 1183, which two years ago privatized liquor sales in Washington.
KXLY-TV of Spokane reports that since then, officials in Kootenai County, Idaho, have seen an increase of $7 million in liquor sales each year.
The Idaho State Liquor Division says Kootenai County had the highest growth in the state.
The prices keep customers coming back. A price check for a fifth of Black Velvet on either side of the border, showed it costs $10 in Idaho and $16 in Washington.