Baby who went on US road trip during mom's maternity leave is about to hit all 50 states

This 5-month-old is about to accomplish an incredible feat in her early life, as the youngest member of the All 50 States Club.

Little Harper Yeats has been accompanied by her parents, Cindy Lim and Tristan Yeats, on what has been a 4-month road trip across the United States.

On Oct. 18, they expect to cross the border of Vermont -- making the Green Mountain State the 50th and final destination.

"The real highlight of the trip is being able to make memories as a family on the road and Harper checking off milestones all over the country," Lim told "Good Morning America." "It means so many places around the U.S.A. are going to be unforgettable to us in the years to come."

Editor’s Picks

Boy whose condition keeps him inside for recess patrols with school officer instead

This dinosaur-loving family's baby announcement will have you roaring for joy

Lim and Yeats said seeing all 50 states has always been a family goal. Together, the couple has visited 19 states, but they started the trip all over again after seeing the website of the All Fifty States Club. They then realized their daughter could be the youngest person to visit all 50.

Lim and Yeats are Australian, but live in Canada -- where Harper was born. The family started their nationwide tour in June, weeks into Lim's year-long maternity leave.

After she checks a location off her list, Harper is photographed at each state line.

"We don't stay in every state, but we do try and and spend a little time in some places," Lim said. "She's like any baby, she has good and bad days, but as long we give her what she need she's very adaptable. I'd like to think [this trip] affected her positively."

The family has applied for the Guinness World Record for the youngest child ever to visit every state in the country. Guinness must consider creating the record before Lim submits the evidence on Harper's trip, she said.

"Based on the info on the All Fifty States Club, we suspect she is going to be the youngest," Lim said, adding that the youngest person listed is two years old.

Lim and Yeats are looking forward to showing Harper pictures of her U.S. trip as she grows up, they said.