An efficient, long lasting identification and trail light that is suitable for marking trails and objects for nighttime identification includes a translucent housing with an internal cavity. A folding tack is mounted on the housing and is movable from a folded away storage position to an extended position for temporarily tacking the housing to an object. An electrical control circuit with a battery are suitably mounted within the cavity. A light is mounted on the housing and is connected to the control circuit. A photocell is connected to the control circuit to actuate battery power to turn on the light in darkness to identify an object or illuminate a trail.