The House rejected an amended omnibus package of more than 160 public lands, water and resources bills despite a last-minute change designed to ease concerns about the bill.
By a vote of 282-144, the House failed to pass S. 22 under a suspension of the rules, which barred any amendments from being added to the bill but also required a two-thirds majority for passage.
The bill would have designated more than 2 million acres of wilderness in nine states and established three new national park units, a new national monument, three new national conservation areas, more than 1,000 miles of national wild and scenic rivers and four new national trails. It also would have enlarged the boundaries of more than a dozen existing national park units and established 10 new national heritage areas.
It also would have authorized numerous land exchanges and conveyances to help local Western communities address water resource and supply issues, and included provisions to improve land management.
"This is the most important piece of conservation legislation we will likely consider this year and possibly in this entire Congress," House Natural Resources Chairman Nick Rahall (D-W.Va.) said on the House floor before the bill's rejection.
The House Democratic leadership had held off bringing the bill to the floor since the Senate passed the package in January while they attempted to gather enough support for the bill to pass it under suspension.
Any changes to the bill would have required sending it back to the Senate, where it would again have faced objections by Sen. Tom Coburn (R-Okla.), before it could go to the White House.
Ultimately, Democrats chose to bring the bill to the floor under suspension but amended it to include language by Rep. Jason Altmire (D-Pa.) designed to ensure that the omnibus would not close off lands that are already open to hunting and fishing.
Rahall said the inclusion of the provision helped clear up many of the concerns some groups, including the National Rifle Association, had with the omnibus bill.
But some House Republicans said bringing the bill under a suspension of the rules circumvents the House's authority, given that nearly 100 of the bills in the 1,200-page package have never passed or have had a hearing in the House.
"This is an extreme abuse of considering bills under a suspension of the rules," said Natural Resources ranking member Doc Hastings (R-Wash.). "Any notion that this is just a package of bills already passed by the House is absolutely false."
Reporter Noelle Straub contributed.