On Saturday, May 10, Mueller is inviting the Austin community to a free, 10th birthday celebration at the Browning Hangar and Lake Park from 10:00 a.m. to 1:00 p.m. The birthday celebration will include paddle boating on the lake, hamster balls, a live DJ, food trucks, birthday cake and a giant piñata.. Free giveaways and exciting surprises will join several other family-friendly activities.