Bennet, who will appear with Biden in Colorado on Wednesday, is running for reelection against Republican Joe O’Dea, a Denver business executive.
A spokesman for O’Dea said he opposes Biden’s creation of the national monument, which relies on the Antiquities Act, a 1906 law that empowers the president to safeguard public lands and waters for the benefit of all Americans.
“Joe believes conservation efforts around Camp Hale and the TenMile Range should be determined by a bipartisan process in Congress, not unilateral and potentially unlawful executive action that could be subject to lawsuits and uncertainty,” spokesman Kyle Kohli said in an email.
A Bennet campaign spokeswoman declined to comment, noting that the appearance with Biden is being organized by Bennet’s Senate office.