This year for Junior Ranger Day, YOU become the scientist! When the missions were built in the 1700s, people had very little technology to help them map the South Texas landscape. Scientists now use new technologies like GPS to help study and preserve the missions! Challenge yourself with our "GPS with the NPS" activity on Sunday, April 21 and earn your very own special Junior Ranger patch after completing the activities. The event is free, and participants may drop in at any time from 10 am - 2 pm. Pick up your activity booklet in the Visitor Center at Mission San José. This is an official National Park Week event.