Lemmus trimucronatus 3 Sept -cont- A sudden sharp decline in temperature - into the -40° F region. This coupled with a very thin snow cover may have been the factor that caused the high mortality that was evident from spring conditions. September Barrow-Dwara R-Plant Boy Three ground checks were made for lemming sign. #1. At a point near the 1966 duck camp site on the Dwara R - actually at the sand dunes down river from the camp site (see 1966 notes). In 2070 paces, covering a lake margin, river bank and large center marsh with dwarf shrub. (myriades worth) on the views of the polygons, I saw no fresh sign of lemming (looked for pellets, fresh runways, fresh burrows). Old sign good everywhere - runways, holes, dried cuttings drifted up in piles, winter nests - some of which had chewed-up remnants, and pellets. #2 - point on the Dwara ca 30 mi.