Gov.Sarah Palin is a grandmother. The baby's name is Tripp, and he was born early Sunday morning, People magazine is reporting.

Palin's daughter, Bristol, gave birth to the healthy 7-pound, 4-ounce baby in the Valley, the magazine reported on its Web site.

The full name: Tripp Easton Mitchell Johnston.

The baby's father is Levi Johnston of Wasilla. News of Bristol's pregnancy broke across the country after Sen. John McCain chose Palin as his running mate in the 2008 presidential election. Johnston soon joined the Palin family on the campaign trail and told The Associated Press in October that the two planned to marry.

Both Johnston and Bristol Palin are 18.

Palin's father, Chuck Heath, declined to comment Monday, referring questions about the baby to the governor and her husband.

The governor's office, which issued a news release when Palin gave birth to her youngest son, Trig, in April, did not return messages Monday.