Caleb Thompson, left, a Kirkmont Center employee, discusses the differences between the fen the boardwalk they are standing on crosses, which constantly has moving water flowing through it, and bogs, which have stagnant water. The Kirkmont tour was part of an Earth Day celebration hosted by LoCo Arts on Saturday that included musical presentations and discussions by Geoff Kaufman, an environmental activist and musician who performed a residency at Benjamin Logan Elementary School last week. (EXAMINER PHOTO | REUBEN MEES)