Following the lead of other states, ‘squares' of approximately 3 miles on a side are based on readily available 7.5 minute Quad topographic maps, dividing each map into 6 regions: top left, top right, center left, center right, bottom left and bottom right. These divisions would result in squares approximately 3 miles on a side. Note that the width of the square changes from the northern to the southern part of the state because it is based on the longitude, which makes a triangle from the north pole to the equator. In Utah County, the squares are approximately 3 1/4 miles wide and 2 7/8 miles high.

Utah is covered by 1541 7.5 minute maps, the edges of which overlap adjoining states. This means there are over 9000 3x3 squares in the state. Since this is an unmanagable number, only 1 square will be sampled for every 2 7.5 Minute Quad topographic map, or 8.3% of the land area, yielding 770 squares.

For convenience, all possible squares are numbered based on numbering the 7.5 minute Quad maps beginning at the top left corner of the state, proceeding right, then down producing a 4 digit number; to which the square number, 1 to 6 is appended. The numbers 0, 7, 8, and 9 are not used. This yields a 5 digit number identifying each square in the state. All birding organizations in the state will use the same numbering scheme enabling data from each survey to be combined easily.

Square number 4 has been selected from every second Quad Topographic map. Since the square chosen is arbitrary, alternate squares from the same topographic map can be chosen if there is good reason.

A note about the maps. The northern and southern borders of Utah were supposed to be on 42° or 37° respectively. They aren't, mostly because of the abilities of the early surveyors. Apparently the law favors the original survey of a boundary, so the borders have not been straightened. Due to this, many of the Quad maps along the north and south borders of the state contain a small sliver of Utah land, and therefore are not included in the selected squares, but are listed in the 7.5 minute map listing for completeness.