Mt. Hale via North Twin, herd path, Fire Warden's Trail

Light frozen slush at beginning became deeper with large footprints higher up. Water flowing in many places. The very pretty Fire Warden's trail had deep snow on the ridge but was still solid enough so that only microspikes were needed on the whole trip. Clouds parted on the way down for a nice view of Mt. Washington in the sun above an undercast. A cairn marks the junction of the FWT but GPS is a big help in finding it. Does anyone know the history of the birch glade? Natural or was there some previous thinning to select only birth? 9 winter 48 to go!