This is the fourth in a series of weekly blog posts covering conservation topics with a focus on protected areas and the laws and institutions that support them (or don’t).

For the past four years, members of Congress have debated whether or not to allow border patrol agents additional access to public lands for national security purposes.

In 2011, an act with a pro-conservation title (H.R. 1505: the National Security and Federal Lands Protection Act) was introduced. The proposed bill would grant the U.S. Customs and Border Protection access to all public lands within 100 miles of the U.S. borders of Mexico and Canada. Within these large swaths of land, sixteen environmental laws would be waived including the Endangered Species Act, the Wilderness Act, and the National Environmental Protection Act (NEPA). Why? So that the border agents could patrol, build roads, fences, or other infrastructure for national security purposes without the burden of cumbersome environmental regulations. Later that year, the bill was amended to only apply to lands within 100 miles of the US-Mexico border. Various iterations of the bill have been proposed for the last several years, but nothing has been passed. I’m going to call all of the related bills the “border bill” for simplicity.

What is the latest on the border bill?

H.R. 399 and S. 208 are active bills currently being considered by Congress. Pew has created a map to show the lands that this bill would affect. As you can see on the map, the border bills would allow access to iconic parks such as Saguaro, Big Bend, and Carlsbad Caverns National Parks.

A separate but related border bill in Arizona (S. 750: Arizona Borderlands Protection and Preservation Act) would allow patrolling, surveillance, and equipment deployment in border lands. However, there is no mention of infrastructure or other construction in the full text. The map here shows the lands that this bill would affect.

What is so interesting about this legislation? Like many political debates, this is all about values, pitting national security and immigration reform against public land management and environmental stewardship.

Proponents of the bill argue that the government should do everything in its power to protect national security. They argue that immigration is out of control and that the border should be secured by any means necessary. Debates can get testy. Recently, John McCain responded to a question from Senator Carper of Delaware about the bill: “In all due respect, frankly, I don’t give a damn if somebody that lives in Delaware doesn’t like my efforts.” Proponents see immigrants as a threat to national security; border crossings are also linked to exacerbated drug and human trafficking.

Opponents, however, state that this bill would be destructive to the environment. Because the bill would waive environmental laws, the Customs and Border Patrol could avoid completing Environmental Impact Assessments required by NEPA which often delay projects but also allow for more environmentally friendly project design. Because these border bills waive the Endangered Species Act, arguably the strongest conservation law in the U.S. (if not the world), endangered species found in these areas could be put at substantial risk. Infrastructure projects – roads, fences, helipads, patrol bases – could themselves fragment habitat and disturb wildlife in sensitive areas.

These border bills, if passed, would constitute a systemic downgrade of protected areas such as National Parks and National Monuments. Downgrades are one type of legal change encapsulated in the concept of PADDD – protected area downgrading, downsizing, and degazettement. You can explore the myriad protected areas that these border bills could affect on PADDDtracker.org.

If passed, it is unknown exactly how much of a toll these bills would take on the environment and to what extent they would enhance security. Although the bill does provide Customs and Border Patrol with access to large swaths of land, the agency may not effectively need access to very distant areas from the border. It is possible that the debate about the border bills is a NIMBY (not in my backyard) issue – constituents of Arizona and other border states may feel differently about the border security issue because it is more of a local concern for them.

It is difficult to summarize this complex issue. Overall, values are driving the political dispute over border security and public lands. Given the current political climate, the border bill debate is likely to continue without a resolution.