The
pattern at QuiltersCache is annotated as an original.
However the Chisholm Trail
block is in the Public Domain. The image below was generated in EQ6. This version was published in the Kansas City Star, year unknown. The only difference is that it's made with quarter-square triangles and half-square triangles instead of flying geese, squares and half-square triangles.
I've added the illustration and links to other patterns for the same block as a bonus for those who prefer to use instructions with fewer copyright restrictions.
http://www.nmia.com/~mgdesign/qor/styles/classicblocks/classicblocks.html
http://www.northstarquiltguild.org/November.pdf