Karl Herbert Merrill (September 1, 1900 – December 2, 1984) was an American farmer who established the Trina line of Holstein cow in 1961, beginning with Trina Redstone Marvel, or "Old Trina", which was traced back sixteen years to one of the first cows imported into the United States from the Netherlands.

[1][2] Today, there are thirty generations of Trina Holstein offspring.

He attended school in Gray, and graduated from Hebron Academy in 1918.

[6] It was renamed Wilsondale Farm when the Wilson family purchased it in 1961.

He is interred in Gray Village Cemetery, beside his wife, who predeceased him by seven years.