Overnight cloud cover thinned/dissipated toward sunrise allowing a rapid temperature drop.  In the Lower Salt River Valley clouds hung around longer and as a result minimums were only near zero.  However, from about Thayne southward it cleared and was much colder.  Following are the observed minimums in the valley this morning.

Auburn                -17
Afton                   -13
Thayne ES           -8
Osmond ES          -8
Smoot                   -5
Etna ES               -1
Star Valley Ranch  2
Alpine                   3

Nearby it was:

Pixley south of Cokeville   -21
Driggs ID                         -17

Cokeville                          -15
Jackson Airport                -13

In other areas clouds were not a factor and as a result it was much colder.

Old Faithful             -33
West Yellowstone    -35

and the coldest was a -41 at the Peter Sink Site which is located just south of Logan Summit Utah west of Bear Lake.  This high elevation sheltered site is typically one of the coldest around.