It appears that these two young resourceful men have turned a cow pasture into a pool table of sorts. On first glance, I thought they were playing with “cow pies” and golf clubs. But upon closer inspection, Clifford Edward Coffey and Max Royhl are indeed using pool balls and cues out on the open plain.
This photograph comes from the Palmer Sigvald Gilbertson Collection. Palmer Gilbertson was a student at the University and graduated in 1915. Born to Ingeborg and Gilbert P. Gilbertson on September 23, 1891, Palmer grew up in Vermillion and was also a graduate of Vermillion High School.
More information at Digital Library South Dakota: http://dlsd.sdln.net/cdm4/document.php?CISOROOT=/photograph&CISOPTR=648&REC=1