Mr. Earl Treadwell lived in Pennellville, a hamlet near Lake Ontario in west-central New York State.

https://en.wikipedia.org/wiki/Pennellville,_New_York

In December of 1915, Earl received a postcard from Martin.

Martin wrote from Albuquerque, the old city on the Rio Grande in the center of New Mexico.

https://en.wikipedia.org/wiki/Albuquerque,_New_Mexico

The face of the postcard is an illustration of a young woman landing a fish.

The woman’s efforts at fishing seem to be well-rewarded.

The legend identifies the young lady as “Miss Isaac Walton”.

Isaac Walton, or Izaak Walton, was an Englishman who published an unusual book, “The Compleat Angler” in 1653.

This book, one of the first English-language books on the sport of fishing, also includes meditations on “Angling”  as a particular gift of the “English” and the sport as an appropriate diversion for Anglicans.

(Walton was a friend of John Donne, and wrote an important biography of this friend.).

https://en.wikipedia.org/wiki/Izaak_Walton

Lovers of the sport of fishing established “Isaac Walton Leagues” across the USA to promote the conservation and preservation of rivers and streams for fishing.

https://en.wikipedia.org/wiki/Izaak_Walton_League

For this postcard artist, “Isaac Walton” is a synonym for “loves fishing”.

I could not find an indication of the artist (or photographer) nor of the postcard publisher.

On the reverse, Martin inquires how Earl is doing, and reports that there was a dusting of snow in Albuquerque.

The snow of the morning was “all gone” by the time Martin set out to write his postcard.

It is possible that the postcard, mailed on December 30, was intended as a New Year greeting – although Martin does not mention the arrival of 1916.

One hopes that Earl and Martin enjoyed the winter and that they remained friends and correspondents for many years.