It's been coming for years. But now the U.S. Census says they believe that Houston County's population has passed Bibb County's.
This week, the Census released their population estimates for July 1, 2017.
They put Houston's population at 153,479 -- about 600 people more than Bibb's.
Bibb County had about 43,000 more people in the 2000 census and about 15,000 more seven years ago.
But their population stayed flat and then dipped slightly as Houston's continued to grow.
Since the 2010 census, the federal agency estimates that Houston has gained nearly 2,000 people a year while Bibb lost about 400 people a year.
The census says the growth comes in three areas:
-- Natural growth -- the difference between births and deaths in the county. The census says Houston gains nearly 1,000 residents a year that way, Bibb nearly 600.
-- Domestic migration -- the difference between the number of people moving into the county from other places in the United States and people moving out.
Houston's population increases by about 570 people a year in that way while Bibb loses about 1,230.
-- International migration -- immigrants from other countries. Houston gains about 370 new residents a year that way, nearly twice as many as Bibb.
Those 2017 census estimates are unofficial and won't be confirmed until the 2020 census.