Happy Birthday, Carrie! Keystone, South Dakota, is celebrating Carrie Ingalls Day on Aug. 3rd. Every year the hold the event on Carrie’s actual birthday. Carrie, Laura’s little sister, was a longtime resident of Keystone. She moved to Keystone in 1910 when she married mine owner and widower David Swanzey. Keystone invites children and adults to dress in “Laura” costumes and participate in many activities planned from 10 am to 3 pm at the Keystone Area Historical Society Museum.