A group of fifth graders from Three Rivers Elementary in Sunriver will be experienced the first "Outdoor School" in the Deschutes Children's Forest this week.  Larry Berrin with Northwest Outdoors says they believe this is just the beginning of a very busy season for the Children's Forest.  He says they are partnering with several organizations: one being the healthcare community, with a program called Prescription to Thrive:  "Where pediatricians are actually going to write prescription to families that have children that have either too much screen time or have issues with obesity and prescribe them activities they can do in the outdoors to get them active, as part of the health angle of our Children's forest. So it's really just a large effort to bring all these things together and just create this culture of activity and learning in the outdoors in Central Oregon."  Berrin says the forest is also open to tourists families that want to experience a learning environment.  The "Outdoor School" will be held in an area at Cultus Lake Resort, and Berrin says the resort is donating services like cooking the meals and providing lodging for the three day field trip.