President Biden on Wednesday announced the creation of the country’s newest national monument, protecting tens of thousands of acres in the mountains of Colorado from mining and development and delivering an election-year gift to Michael Bennet, one of the state’s two Democratic senators.Standing on the grounds of Camp Hale, a World War II military installation that was used to train the U.S. Army’s 10th Mountain Division, Mr. Biden said he was designating 53,804 acres of rugged landscape as the Camp Hale-Continental Divide National Monument.“When you think about the national beauty of Colorado and the history of our nation, you find it here,” the president said moments before signing the proclamation. He pointed to the area’s highlights: “the Tenmile Range, soaring peaks and steep canyons, black bears, bald eagles, moose, mountain lions, wonderful pristine rivers, alpine lakes.”“These treasured lands,” he said, “tell the story of America.”Mr. Bennet has tried to make public land preservation central to his image in outdoor-obsessed Colorado. In March, Mr. Biden signed a measure by Mr. Bennet that established Camp Amache, a World War II detention center for Japanese Americans in southeastern Colorado, as a National Park Service historic site.But Mr. Bennet is in a tougher-than-expected re-election race against Joe O’Dea, a first-time candidate and the head of a Denver construction company who has won the support of national Republicans.In contrast to Republican Senate candidates elsewhere, Mr. O’Dea is running as a moderate and has broken with former President Donald J. Trump. Mr. Bennet is the favorite, and, with the election weeks away, the backing from the White House for the national monument could help raise his profile and demonstrate his influence.Standing next to Mr. Biden, Mr. Bennet thanked the president for the decision to use his executive authority to designate the new monument.The State of the 2022 Midterm ElectionsWith the primaries over, both parties are shifting their focus to the general election on Nov. 8.The Final Stretch: With less than one month until Election Day, Republicans remain favored to take over the House, but momentum in the pitched battle for the Senate has seesawed back and forth.A Surprising Battleground: New York has emerged from a haywire redistricting cycle as perhaps the most consequential congressional battleground in the country. For Democrats, the uncertainty is particularly jarring.Pennsylvania Governor’s Race: Attacks by Doug Mastriano, the G.O.P. nominee, on the Jewish school where Josh Shapiro, the Democratic candidate, sends his children have set off an outcry about antisemitic signaling.Herschel Walker: The Republican Senate nominee in Georgia reportedly paid for an ex-girlfriend’s abortion, but some conservative Christians have learned to tolerate the behavior of those who advance their cause.“You ensure that, years from now, we can bring our kids, grandkids here and tell them the story of the 10th Mountain Division and their contributions not only to Colorado but to humanity,” Mr. Bennet said. He added, “And for that, Mr. President, Colorado will be forever grateful.”When it was his turn to speak, Mr. Biden joked that Mr. Bennet would probably be grateful, too.“This guy, he made this finally happen,” Mr. Biden said, grasping Mr. Bennet’s hand. “He came to the White House and he said, ‘I told you what I need.’ And I said ‘I’ll do it.’ You know why? I was worried he’d never leave the damn White House.”Mr. Biden greeted officials and members of Colorado’s congressional delegation in Vail.T.J. Kirkpatrick for The New York TimesThe president’s use of his executive authority under the Antiquities Act to designate the Camp Hale national monument came after nearly a decade of efforts by Democrats to pass legislation to protect the area from mining and timber operations.Republicans accused the president of an “end run” around Congress. In a letter late last month, 11 Republican lawmakers, including Representative Lauren Boebert of Colorado, lashed out at Mr. Biden.“For years, partisan big-city Democrats — with the full backing and support of the far-left green energy cartel — have attempted to implement massive new land grabs,” the lawmakers said, noting the failure of legislative efforts to protect the area from development.“We don’t support the efforts of extremist environmentalists who are seeking to hijack this historic place to create a new land designation — a designation that literally does not exist — to prohibit timber harvesting and mining on nearly 30,000 acres of land,” they wrote.Camp Hale, not far from the popular ski areas of Vail and Breckenridge, was used during World War II to train Army soldiers for battles against the Axis forces in the Italian Alps. According to the White House, the soldiers learned “winter survival techniques and to snowshoe, to climb and, most famously, to ski.”In his remarks on Wednesday, Mr. Biden cited the historic role that the site played during World War II and the importance of the land to Indigenous people in the area.“For thousands of years, tribal nations have been stewards of this sacred land, hunting game, foraging medicinal plants and maintaining a deep spiritual bond with the land itself,” he said.The area around the camp had long been important to the Ute Tribes, who were forced off their ancestral homeland in the mid-1800s. The new monument, which sits within the White River National Forest and includes the Tenmile Range, will continue to be used for skiing, hiking, camping and snowmobiling, officials said.In a description of the proclamation the president signed, White House officials said the Ute people returned to the area frequently, to “pray, hold ceremonies, honor their ancestors, hunt, fish and harvest plants.” Officials said the effort to protect the area for recreation and ecology would also safeguard Ute burial sites that are thousands of years old.This is the first time that Mr. Biden has created a national monument through the 1906 Antiquities Act, which Theodore Roosevelt first used to establish the Devils Tower National Monument in Wyoming. Since then, 18 presidents of both parties have used it to designate monuments, including the Grand Canyon, the Statue of Liberty and Colorado’s Canyons of the Ancients, officials said.But Republicans said Mr. Biden was abusing the law in the case of Camp Hale. In their letter, the Republican lawmakers wrote that the president was trying to “weaponize the Antiquities Act,” calling it “an outdated 1906 law.”The partisan back-and-forth underscores the political backdrop for the president’s announcement.Democrats are counting on Mr. Bennet to win re-election in the midterm elections as they work to keep control of the Senate. If Republicans make a net gain of just one seat, they will regain control and the ability to shape the agenda in the chamber for the next two years.With Control of the Senate in Play, These Are the Races to WatchWith the Senate knotted at 50-50 for each party, Republican control is only one seat away. But the elections have been full of surprises.Losing control of the Senate and the House of Representatives would dash any hope that Mr. Biden has of making more legislative progress in the last two years of his term.Mr. Biden also announced a plan on Wednesday to deny new mining for gas and minerals on about 225,000 acres of the nearby Thompson Divide, a vast area that offers expansive wildlife habitats, recreation opportunities and grazing lands, officials said.At Mr. Biden’s direction, the Interior Department and the Agriculture Department will begin a process to prohibit new mining leases on the land for the next 20 years. The president also announced that $4 billion from the Inflation Reduction Act would be spent to mitigate drought in the Lower Colorado River Basin System Conservation and Efficiency Program and invest in the Upper Colorado River Basin.Both are programs backed by Mr. Bennet.Carl Hulse More