"Eldora Newspapers: About Us". eldoranewspapers.com (Eldora Herald-Ledger) website. Eldora, Iowa. Archived from the original on February 17, 2021. Retrieved February 16, 2021.
Samuel Walker Beyer, Geology of Hardin County, Iowa Geological Annual Report 10(1) 1899; pages 241-314, see map between 278,279, see pages 252-253 for topography and page 246 for historical woodland.
"Eldora Newspapers: About Us". eldoranewspapers.com (Eldora Herald-Ledger) website. Eldora, Iowa. Archived from the original on February 17, 2021. Retrieved February 16, 2021.