1910 — Theodore Roosevelt, African Game Trails: An Account of the African Wanderings of an American Hunter-Naturalist, Charles Scribner's Sons (1910), page 521:
There was nothing to shoot at; but a moment afterward I saw a pair of horns through the grass tops, in such a position that it was evident the owner was looking at me.
Motionless again, only his brown cap showing above the grass tops, he fixed his gaze on an open space some two hundred yards ahead.
1945 — John Joseph Matthews, Talking to the Moon: Wildlife Adventures on the Plains and Prairies of Osage Country, University of Oklahoma Press (1981), →ISBN, page 235:
I could see by the waving grass tops that the wind was out of the south, and this gave me an idea.