Ms. Mesinai, however, said that prisoners returning from Russia well into the 1990s claim to have seen Mr. Wallenberg, and that those Russian documents are “fraught with contradictions” and might have been forged. 

Further, the Parks Department’s current sign states that Mr. Wallenberg issued counterfeit Swedish “passports” to Jewish people — but those documents, according to Ms. Mesinai, were actually protective “schutz” passes. The sign also refers to the eyewitnesses as Russian prisoners, but Ms. Mesinai said those released prisoners were of various nationalities, not just from Russia. 

For Ms. Mesinai, the accuracy of the sign is of the utmost importance — both for those who frequent the park today and especially for future generations. 

“Kids play there. They’re going to see that over and over again, and it’s going to be the truth, whether it is or not. Obviously, he’s over 100 now, he’s gone, but it doesn’t make any difference in terms of what he gave the world and what we owe back to him,” she said. 

Riverdalian Tom Bird, a member of the Bronx Council for Environmental Quality who co-founded the Riverdale Nature Preservancy, said the sign’s inaccuracies were an affront to the intricate history surrounding Mr. Wallenberg’s plight.

“It deserves the accurate, correct, lawful linkages,” he said of Mr. Wallenberg’s legacy.

As for the Parks Department, Ms. Kiernan said it welcomed input from the community.

“We’re happy to see so many people reading our historic signs and very much appreciate the community helping us to keep these signs up to date,” she said.