First, the prehistoric artist prepared the rock surface by scraping the surface smooth removing the less-consolidated exterior sandstone surface to expose the harder inner layer for incising and painting. Next, the artist deeply incised the pattern of a circular shield or shield-bearing warrior. Incised images could have been made with a variety of stone, bone, antler or metal tools depending on the hardness of the rock surface. Also, abrading or smoothing the rock surface was likely done with a stone block or flattened cobble. Often, the shield is divided into quadrants or pie-shaped sections by incising geometric or animal forms. Once figures/shapes were incised, the artist filled in the figures with several layers of paint. Colors included two shades of red (one more purple than the other), two shades of orange (one more yellow than the other), black, white and green. Polychrome painting and the use of green pigment are very rare in Wyoming and serve as distinguishing characteristics for the Castle Gardens shield style. The Great Turtle figure (housed at the Wyoming State Museum) exemplifies many of the hallmarks of this style.