National Park Service spokesman Mike Litterst said the service does not have information about rapes and murders readily available and did not provide it to Coburn's office.
Sen. Barbara Boxer, D-Calif., the author of the water projects bill that Coburn sought to amend, argued that Coburn's proposal didn't belong on the legislation.
“This is not a gun bill,” she said. “This is not a place to add these types of amendments … It isn't necessary; it isn't appropriate.”
Boxer also complained that Coburn's amendment would allow people to carry weapons at dams and locks and other infrastructure that could be vulnerable to terrorist acts. Coburn said a separate federal law prohibited carrying weapons at such critical structures and that his amendment would not affect that law.
The debate came less than a month after Senate leaders shelved a gun control bill. Coburn, who has been a fierce defender of Second Amendment rights, was heavily criticized in Oklahoma for voting to advance that bill past a procedural hurdle so it could be debated. Coburn later voted against a bipartisan proposal to expand background checks and others to ban certain weapons and ammunition clips.