Within hours of taking office, President Joe Biden signed an executive order rescinding the permit for the Keystone XL pipeline.
The move has halted construction of the nearly 1,200 mile (1,930 km) cross-country US-Canada project. It's the latest - and possibly final - chapter in an effort to build the pipeline that has led to protests, legal battles and political lobbying that have now spanned the administrations of three US presidents.
Here, in their own words, are some of the people - ranchers, politicians and environmental activists - on either side of this decade-long fight.
Jane Kleeb is founder of political advocacy group Bold Nebraska and Chair of the Nebraska Democratic Party
I started Bold in 2010 as an organisation that was going to focus on a bunch of issues and bridge the urban and rural divide in the state. But then about three months after we launched, I started getting phone calls from farmers and ranchers saying people were knocking at their doors, telling them if they don't give their land over to this pipeline company that they're going to use eminent domain (taking private land and converting it into public use) and not give them any money for their land.
I knew nothing about pipelines or eminent domain, but I knew a lot about ranchers and this didn't make any sense. So I just started to do my own homework.
I was shocked by the amount of opposition that had self-organised against the pipeline right in the beginning. So I said to myself, if we really put some plans around this, we can win this.
We just started doing education sessions in church basements, bars, cafes, libraries - anywhere that ranchers asked us to come. There was no silver bullet or magic to the work we did. It was just a lot of hard work.
About four years into the fight, in 2014, we organised a big protest on the National Mall in Washington. That was the first time the Obama administration ever called me. They were like 'OK. You have our attention now.'
I did not think that Biden was going to do this so quickly. And so when I realised this was finally going to be the day that the pipeline was rejected, I was just filled with a tremendous amount of joy. There's joy that this totally unlikely alliance from different political ideologies went up against the Canadian government, the Republican government, half of the Democratic party and the oil industry, and we won.
'This hurts my town'
Douglas Irving is mayor of Hardisty, Alberta
We're disappointed. It obviously hurts the town. The first section of the pipeline was from the Saskatchewan border to a small town named Oyen. This year's construction season would have been from Oyen to Hardisty.
Our population is just 540 people but we have about 600 hotel beds. We're geared for construction season - providing accommodation, meals and services.
My belief is that the pipeline will get built eventually with the need to create American jobs. I'm in favour of construction and development over the environment. I think the environment portion of the debate is overrated. We're just cutting our own throats to say we're green.
I don't think people objecting to the pipeline have ever seen a pipeline going into the ground. Compared to tankers travelling around the world, trains taking oil out, it's a very safe system.
We have a lot of pipelines in and out of Hardisty and a year after they're in the ground and the soil is put back, the farmers are growing crops and the cattle are back grazing.
I think that people who are thinking that we'll all be electric in 20 years are way out and dreaming. I think we'll have oil for a long, long time.
'Leave that sludge in the ground'
Dr James Hansen is a NASA Climate Scientist
This decision is important. I've said that it's 'game over' for climate if we move from conventional fossil fuels into unconventional, which are even dirtier and more carbon intensive. Terminating Keystone XL gives us a chance to avoid a big leap into that big mess. It's stop-gap action.
Pipelines are superior to other methods of moving oil - tankers, trains - but that's the point. We must leave that sludge in the ground and retain the healthy forest above. Pipelines would let this tar sands travesty continue longer, with our young people paying the price.
'This is devastating for us'
Alvin Francis is chief of Nekaneet Cree First Nation in Saskatchewan, part owner of Keystone XL
The reason we supported the pipeline is because these economic opportunities are few and far between, especially a big project like this.
There are 542 people that live on my First Nation and we have unemployment of over 50%. I've got to think about my young people. I'm between a rock and a hard place when it comes down to being a cultural leader and a businessman. When these opportunities come I have to jump on them. I'm not going to sit back and watch them go through my traditional territory when there's an opportunity to seize.
The news has been devastating for us. Our young people came up to me and said 'now what are you going to do?' It's on me now. I have to go out there and try to find more opportunities for them.
It's politics right? Joe Biden is separating himself from Trump.
To me, the question is - how do we make this the safest pipeline in the world? How do we make it environmentally friendly? TC Canada, my partner, is trying its very best to put its best foot forward to make this the safest pipeline, to make sure this pipeline is successful. There are other resources out there to make the world more safe, but we're not there yet.
'A sense of relief'
Angeline Cheek is an activist and organiser from the Fort Peck Assiniboine Sioux Tribal Nation
I feel a sense of relief. I feel like it's been a long journey. I faced criticism from certain people in our area who wanted to benefit from the pipeline financially but it didn't stop me from organising.
The pipeline was going to be just a quarter of a mile from the borders of the Fort Peck reservation. We're in Montana just 60 miles south of the Canadian border.
If you take a look at these pipelines, they're all going near the borders of the reservations. I see it as an act of genocide, another way to destroy our people, just like how the government tried to strip us of our culture and our ceremonies.
In August 2019 I went to Alberta for an Indigenous climate action workshop. I was able to witness and talk to people who live in the tar sands area and see what a detrimental effect it had on their community, on their people.
Water is the last resource we have for our people. Being Lakota or Dakota - part of the Sioux Nation - I think that it's our job to protect it.
'Time for clean energy'
Art Tanderup is a farmer and landowner on the pipeline route in Neligh, Nebraska
We're very excited about the decision. Obviously there's a little bit of caution. In 2015, after Obama rejected it, it only lasted until the next president.
We've been involved in the fight for about 10 years now, since TransCanada [now TC Energy] came knocking at our door and wanted to put the pipeline across our land.
At the beginning, we were offered about $20,000 (C$25,300) but we knew we never wanted this thing. One of my neighbours across the road was given over $80,000. We've been standing alone out here. The neighbours all around me have signed. I have to go about five miles one way and about 10 miles the other way to find a farmer that did not sign with TransCanada.
We're right above the Ogallala Aquifer. It is the greatest fresh water source in the United States. If the pipeline were to leak, it would go directly into the aquifer. Over the years, nobody - TransCanada, politicians, scientists - has come up with a way to clean it up if it were to be poisoned. This is the dirtiest of fossil fuels, and it needs to be left in the ground.
For people who talk about the jobs, they don't talk about the landowners out here and how it impacts their lives and the jobs that we do raising clean food and fibre for this country.
There are plenty of jobs that pipeline workers can do. It's time to do some retraining and become involved in the clean energy labour force, which is growing tremendously.
'This destroys the economy'
Chris Bloomer is president and CEO of the Canadian Energy Pipeline Association
This is really political symbolism. And it's a backward looking decision because it doesn't really take into account what the project is today. As a result, a project has been shut down that was creating thousands of jobs, with long-term benefits on both sides of the border. This is a loss of billions of dollars of future revenue. It's a massive number.
The opposition has piggybacked on the false narrative that pipelines aren't safe and that any leak is going to be absolutely cataclysmic. That isn't the case.
Pipelines are going to be there for the foreseeable future - decades and decades.
The pushback really is on the oil and gas use and all around the transition away from oil and gas. But the issue is - this transition is not going to happen overnight, and you can't destroy the economy to achieve that.
Interviews condensed and edited for clarity.