The sources for illustrations used in this publication are shown below. Dates when each of the photographic illustrations was taken are noted, if known, in parentheses. Department of the Interior, National Park Service has been abbreviated to DINPS for use in designating illustrations supplied by the NPS. The numbers to the left correspond to figure numbers under the illustrations in the text.

1. Report of a Geological Survey of Wisconsin, Iowa, and Minnesota; and incidentally of a portion of Nebraska Territory, 1852, page 196.

2. Figure 64, page 127, South Dakota School of Mines Bulletin 13, November 1920.

3. Report of a Geological Survey of Wisconsin, Iowa, and Minnesota; and incidentally of a portion of Nebraska Territory, 1852, between pages 196 and 197.

4. DINPS (November 20, 1967). Note: The Badlands Natural History Association is grateful to Mr. Leonel Jensen, local rancher, for help in locating the site of this trail. It is in S1/2 sec. 30, T. 1 S., R. 15 E. of the Black Hills Meridian.

5. South Dakota School of Mines and Technology, Rapid City, South Dakota.

6. The Rapid City Daily Journal, Monday, September 27, 1965.

7. Louis Blumer, Wall, South Dakota (about 1911).

8. A.E. Johnson, Interior, South Dakota (December 1906).

9. Ted E. Hustead, Wall Drug Store, Wall, South Dakota (1907).

10. Plate No. 56B, South Dakota School of Mines Bulletin 13, November 1920.

11. Keith Crew, Interior, South Dakota; from a postcard mailed June 5, 1909.

12. Leonel Jensen, Wall, South Dakota (fall 1908; Louis J. Jensen family).

13. Leslie Crew, Interior, South Dakota; from a postcard mailed December 19, 1908.

14. Rise Studio, Rapid City, South Dakota.

15. Black Hills Studios, Inc., Spearfish, South Dakota.

16. DINPS.

17. DINPS.

18. DINPS (December 6, 1964).

19. DINPS (1938).

20. DINPS (about 1934).

21. DINPS (June 1941).

22. DINPS (June 7, 1950).

23. DINPS.

24. DINPS (spring 1964).

25. DINPS (August 1960).

26. DINPS (September 16, 1959).

27. DINPS (summer 1962).

28. DINPS (July 1962).

29. DINPS (January 9, 1964).

30. DINPS (January 25, 1964).

The Badlands Natural History Association wishes to extend its sincere thanks to these individuals and organizations for granting the association permission to use the illustrations.