The City of Sisters is having an Arbor Day celebration Thursday. David Hewitt's fourth grade class at Sisters Elementary School is joining in the festivities by planting 10 trees to honor the day. "We thought it would be nice to have the fourth graders come out and, for me, it's a nice outreach for the kids to feel like they have contributed something to the community at large and they have an investment out there and it's something they that they'll be able to look back at in several years and say, 'I helped plant that tree over there.' " Hewitt says they will plant 10 trees: five spruce trees and five aspen trees at Sisters Overnight Park, right after a proclamation is read by Mayor Lon Kellstrom. The City received a “Tree City USA” award for the fifth time this year as well as a “Growth Award” from the State of Oregon.