[Clark, December 13, 1804]
13th December Thursday 1804 The last night was verry Clear & the frost which fell Covered the ice old Snow & thos parts which was naked 1/6 of an inch, The Thermotr. Stands this morning at 20° below 0, a fine day. find it imposible to make an Observation with an artifical Horsison Joseph Fields kill a Cow and Calf to day one mile from the fort river falls