Marking a new chapter for the Irvine Public Library system, the Katie Wheeler branch is now open for business.

The library, located in Irvine Ranch Historic Park, wrapped up a months-long renovation and celebrated the milestone over the weekend with a grand opening bookended by festivities for guests who showed up to peruse the branch and its updated amenities.

Katie Wheeler is a third branch for the Irvine Public Library system, a city-run network established last year after Irvine’s break from the Orange County Public Libraries system. A main branch for the independent library system is planned at the Great Park.

The Katie Wheeler branch, dedicated as a historical landmark in 2008, is a modern reconstruction of the 19th-century home, known as the “Irvine Mansion,” that was owned and lived in by James Irvine I.

James H. Irvine, his son, inherited the home, and it was there in 1920 that his first grandchild, a girl named Katie, was born.

But a fire severely damaged the mansion, and the iconic home was demolished in the 1960s. A faithful reconstruction of the original home was built in its place, later becoming the Katie Wheeler library, taking the name of the granddaughter of James. H. Irvine.

The city already had the Heritage Park and the University Park branches open since taking over the county system.

The Katie Wheeler branch at 13109 Old Myford Road will be open 10 a.m. to 8 p.m. Mondays through Thursdays and 9 a.m. to 5 p.m. Fridays and weekends.