BISMARCK, N.D. (G&F) – The state Game and Fish Department’s annual spring aerial mule deer survey is set to begin April 1 in western North Dakota.

Weather permitting, the survey takes about two weeks to complete.

During the survey period, people could notice low-flying small airplanes over some parts of the badlands.

Game and Fish biologists have completed aerial surveys of the same 24 badlands study areas since the 1950s. The purpose of the survey is to determine a population index to assess mule deer abundance in the badlands.