The State of Iowa passed SF 496 in 2023, which was scheduled to go into effect on January 1, 2024, banning any book with a "description or visual depiction of a sex act" from K-12 libraries. Among many other changes, the law also prohibited instruction about gender identity or sexual orientation in elementary schools. Although the "sex act" part of the law was framed as being about children's innocence, it was very clearly motivated by anti-LGBTQ+ sentiments. On December 29, 2023, a federal judge issued an injunction prohibiting enforcement of the book ban and instruction ban portions of the law. Based on the database in this Des Moines Register article, I have noted which districts reshelved books and which did not in response to that injunction. (Note: This is an updated database compared to the original, which stopped being updated in December 2023.) On August 9, 2024, a federal appeals court allowed the law to go into effect. However, the appellate court made it clear that the lawsuit will likely end with the law being overturned for violating the First Amendment.

If you are doing this challenge and come across a book that is clearly wrongly removed by your local school board (e.g., A Separate Peace or Animal Farm, neither of which contains any sex or references to LGBTQ+ people whatsoever), or you live in a district that has not reshelved the books following the injunction, please reach out to the school board of your district. If your district isn't marked below, you can find out from the database in this Des Moines Register article whether your district did or did not reshelve the books.

Adel DeSoto Minburn School Board - Books Not Returned to Shelves
AGWSR School Board - Books Not Returned to Shelves
Alta-Aurelia School Board - Books Reshelved
Aplington-Parkersburg School Board - Books Not Returned to Shelves 
CAM School Board - Books Not Returned to Shelves
Carlisle School Board - Books Not Returned to Shelves
Cedar Falls - Some Books Reshelved
Central Lyon School Board - Books Not Returned to Shelves
Central Springs School Board - Books Not Returned to Shelves
Charles City School Board - Unknown
Clarinda School Board - Books Not Returned to Shelves
Dallas Center-Grimes - Books Reshelved
Decorah School Board - Books Reshelved
Dike-New Hartford School Board - Books Not Returned to Shelves
Estherville Lincoln Central School Board - Books Not Returned to Shelves
Forest City Community School Board - Books Not Returned to Shelves
Gilbert School Board - Books Not Returned to Shelves
Griswold Community School Board - Unknown
Highland Community School Board - Books Not Returned to Shelves
Hudson Community School District Board - Books Not Returned to Shelves
Indianola School Board - Books Not Returned to Shelves
Iowa City Community School Board - Books Reshelved
Keota Community Schools - Books Not Returned to Shelves
Louisa-Muscatine School Board - Books Reshelved
Martensdale-St Marys School Board - Some Books Reshelved
Mason City School Board - DMR article on Mason City removal list (aided by ChatGPT) - Some Books Reshelved
Melcher-Dallas CSD School Board - Books Reshelved
Nevada School Board - Books Not Returned to Shelves
Nodaway Valley School Board - Books Not Returned to Shelves
Northwood Kensett School Board - Books Not Returned to Shelves
Norwalk School Board - DMR article on Norwalk removal list - Books Reshelved
Oskaloosa School Board - Books Not Returned to Shelves
Ottumwa School Board - Books Not Returned to Shelves
Red Oak School Board - Books Not Returned to Shelves
Riverside School District - Unknown
Saydel School Board - Books Not Returned to Shelves
Sigourney School Board - Books Not Returned to Shelves
South Central Calhoun School Board - Books Reshelved
South Tama School Board - Books Not Returned to Shelves
St Angsar School Board - Books Not Returned to Shelves
United Community School Board - See Boone
Urbandale School Board - DMR article on Urbandale removal list (and original removal list) - Books Reshelved
WACO School Board - Books Not Returned to Shelves
Waukee - Some Books Reshelved
Waverly-Shell Rock School Board - Books Not Returned to Shelves
West Des Moines School Board - Books Reshelved
Winterset School Board - Some Books Reshelved
Woodward-Granger School Board - Books Not Returned to Shelves 

Notes:
(1) Challenge prompts for books that have been removed by only one district have been marked "Bonus Prompts."
(2) Series have been consolidated into a single prompt, with all books in the series listed.
(3) This challenge is up to date with original Des Moines Register database information posted up to December 20, 2023. On June 9, 2024, the Register provided an updated database in this article; I will be updating the challenge with this new information as I am able.
(4) Numbering is based on frequency of removal. May be adjusted after adding new books from new database. Currently:
Bonus prompts: 1 district
5: 2 districts
4: 3 to 7 districts
3: 8 to 12 districts
2: 13 to 17 districts
1: 18+ districts