(CNN) The Standing Rock Sioux tribe says a "rogue group of protesters" have put their cause at risk after reports that the 1,172-mile Dakota Access Pipeline project may have cleared a final hurdle.

More than 70 people were arrested near the camp Wednesday as tensions flared again after two North Dakota lawmakers said work will continue on the stalled pipeline.

Now, depending on whom you ask, that last part of the pipeline -- a hotly contested portion under the Missouri River that's been the focus of the massive protests -- could be on the road to completion.

Acting Secretary of the Army Robert Speer "has directed the Army Corps of Engineers to proceed with the easement needed to complete the Dakota Access Pipeline," Sen. John Hoeven said in a statement. Hoeven said he spoke with Speer on Tuesday.

Phil Little Thunder Sr. attends an evening gathering at an encampment of Dakota Access Pipeline protesters on September 3.

Phil Little Thunder Sr. attends an evening gathering at an encampment of Dakota Access Pipeline protesters on September 3.

Flags of Native American tribes from across the United States and Canada line the entrance to a protest encampment on Saturday, September 3.

Flags of Native American tribes from across the United States and Canada line the entrance to a protest encampment on Saturday, September 3.

The Missouri River is seen beyond an encampment near Cannon Ball, where hundreds of people gathered to join the protest on September 4.

The Missouri River is seen beyond an encampment near Cannon Ball, where hundreds of people gathered to join the protest on September 4.

Native Americans ride with raised fists to the sacred burial ground on September 4 to protest the Dakota Access Pipeline.

Native Americans ride with raised fists to the sacred burial ground on September 4 to protest the Dakota Access Pipeline.

Marlo Langdeau of the Lower Brule Sioux Tribe joins hundreds of Native Americans for a march near Cannon Ball on Sunday, September 4.

Marlo Langdeau of the Lower Brule Sioux Tribe joins hundreds of Native Americans for a march near Cannon Ball on Sunday, September 4.

People hang a sign near what they say was sacred burial ground disturbed by bulldozers in Cannon Ball.

People hang a sign near what they say was sacred burial ground disturbed by bulldozers in Cannon Ball.

Native Americans head to a rally at the state capitol in Denver on Thursday, September 8. They were showing their support for members of the Standing Rock Sioux tribe in North Dakota opposting the Dakota Access Pipeline.

Native Americans head to a rally at the state capitol in Denver on Thursday, September 8. They were showing their support for members of the Standing Rock Sioux tribe in North Dakota opposting the Dakota Access Pipeline.

A protester shows where he was hit by a bean-bag round fired by officers trying to force protesters off the private land.

A protester shows where he was hit by a bean-bag round fired by officers trying to force protesters off the private land.

Tires burn as armed soldiers and law enforcement officers stand in formation to force Dakota Access Pipeline protesters off the private land in Morton County.

Tires burn as armed soldiers and law enforcement officers stand in formation to force Dakota Access Pipeline protesters off the private land in Morton County.

Pipeline protesters sit in a prayer circle as a line of law enforcement officers make their way across the camp to relocate the protesters a few miles south on Thursday, October 27. Protesters had camped on private property.

Pipeline protesters sit in a prayer circle as a line of law enforcement officers make their way across the camp to relocate the protesters a few miles south on Thursday, October 27. Protesters had camped on private property.

The burned hulks of heavy trucks sit on Highway 1806 on Friday, October 28, near a spot where Dakota Access Pipeline protesters were evicted a day earlier.

The burned hulks of heavy trucks sit on Highway 1806 on Friday, October 28, near a spot where Dakota Access Pipeline protesters were evicted a day earlier.

Cousins Jessica and Michelle Decoteau take part in a protest outside the North Dakota state capitol in Bismarck on October 29.

Cousins Jessica and Michelle Decoteau take part in a protest outside the North Dakota state capitol in Bismarck on October 29.

Tribe members make their way back to their camp on Saturday, October 29.

Tribe members make their way back to their camp on Saturday, October 29.

Dozens of protesters wade in cold creek waters as they confront local police on November 2.

Dozens of protesters wade in cold creek waters as they confront local police on November 2.

Tonya Stands recovers after being pepper-sprayed by police on Wednesday, November 2. Stands was pepper-sprayed after swimming across a creek with other protesters hoping to build a new camp to block construction of the Dakota Access Pipeline.

Tonya Stands recovers after being pepper-sprayed by police on Wednesday, November 2. Stands was pepper-sprayed after swimming across a creek with other protesters hoping to build a new camp to block construction of the Dakota Access Pipeline.

In this image provided by the Morton County Sheriff's Department, law enforcement and protesters clash near the pipeline site on Sunday, November 20.

In this image provided by the Morton County Sheriff's Department, law enforcement and protesters clash near the pipeline site on Sunday, November 20.

A sculpture stands at an encampment where protesters of the pipeline have been gathered for months.

A sculpture stands at an encampment where protesters of the pipeline have been gathered for months.

People against the construction of the Dakota Access Pipeline speak at a news conference near Cannon Ball on Saturday, November 26.

People against the construction of the Dakota Access Pipeline speak at a news conference near Cannon Ball on Saturday, November 26.

A procession makes its way down to the Cannonball River to take part in a Native American water ceremony on December 1.

A procession makes its way down to the Cannonball River to take part in a Native American water ceremony on December 1.

Dan Nanamkin of the Colville Nez Perce tribe drums a traditional song by the Cannonball River in Cannon Ball, North Dakota, on Thursday, December 1.

Dan Nanamkin of the Colville Nez Perce tribe drums a traditional song by the Cannonball River in Cannon Ball, North Dakota, on Thursday, December 1.

Activists celebrate at Oceti Sakowin Camp on December 4. An executive order by President Donald Trump in January allows work to resume on the Dakota Access Pipeline, which the activists oppose.

Activists celebrate at Oceti Sakowin Camp on December 4. An executive order by President Donald Trump in January allows work to resume on the Dakota Access Pipeline, which the activists oppose.

An activist rides down from a ridge on the edge of the Standing Rock Sioux Reservation on December 4.

An activist rides down from a ridge on the edge of the Standing Rock Sioux Reservation on December 4.

Activists embrace after the December halt of the Dakota Access Pipeline route. The $3.7 billion project that would cross four states and change the landscape of the US crude oil supply. The Standing Rock Sioux tribe says the pipeline would affect its drinking-water supply and destroy its sacred sites.

Fireworks lit the sky at the Oceti Sakowin Camp near Cannon Ball, North Dakota on December 4, 2016, after the Army Corps of Engineers halted the Dakota Access Pipeline route. An executive order by President Donald Trump in January allowed work to resume.

Fireworks lit the sky at the Oceti Sakowin Camp near Cannon Ball, North Dakota on December 4, 2016, after the Army Corps of Engineers halted the Dakota Access Pipeline route. An executive order by President Donald Trump in January allowed work to resume.

Rep. Kevin Cramer, also a North Dakota Republican, said he received word that the Army Corps will grant final approval and that congressional notification of the decision was "imminent."

The Standing Rock Sioux says the lawmakers' announcements are premature, but the tribe's lawyer says they will be prepared for another legal battle if the easement is granted.

On Wednesday, Army Maj. Gen. Malcolm Frost said the easement has not yet been approved.

"The assistant secretary for the Army Civil Works will make a decision on the easement once a full review and analysis is completed in accordance with the directive," Frost said in a statement.

That directive refers to President Donald Trump's January 24 order , "which directs the acting secretary of the Army to expeditiously review requests for approvals to construct and operate the Dakota Access Pipeline in compliance with the law," Frost said.

74 arrested for trespassing near the pipeline

Dozens of people were arrested Wednesday near the pipeline after a "rogue group of protesters tried to establish a new illegal camp on private property, against the request of the tribal council and district leaders," the North Dakota Joint Information Center said.

The property owner asked authorities to remove "the trespassers," the statement said.

Officials met with the group several times and requested the new camp be dismantled and the protesters leave. The group was given time to start dismantling the camp, but showed no signs of leaving.

Up to 74 people were arrested in southern Morton County, the Morton County Sheriff's Office said.

The recent arrests paled in comparison to the number of people arrested at the height of protests. One day in October, police arrested at least 141 people.

Pipeline opponents: We won't back down

The Standing Rock Sioux tribe, which has long opposed the project, said Hoeven's announcement was premature and said further environmental review is needed for the pipeline.

The tribe has been concerned that digging the pipeline under Lake Oahe -- a section of the Missouri River in North Dakota -- would affect the area's drinking water as well as the supply for 17 million people living downstream.

The proposed underground route at Lake Oahe is half a mile upstream from the Standing Rock Sioux tribe's reservation.

Jan Hasselman of Earthjustice , the lead counsel representing the Standing Rock Sioux, said he'll be ready to fight the easement in the event it's approved.

"When it does -- and that could be tomorrow or next week or longer -- there certainly will be a lawsuit filed to determine the legality of it," Hasselman said Wednesday.

He said because there is no current permit to build, any resumed building at this point would be a violation of the law.

In December, protesters celebrated a temporary victory when the Army said it would not -- for the time being -- allow the pipeline to cross under Lake Oahe. At the time, the Army called for an official environmental impact statement -- a monthslong process that would allow the public to weigh in.

The tribe vowed to "vigorously pursue legal action" if the Trump administration cuts off the environmental review and grants the easement.

"To abandon the (environmental impact statement) would amount to a wholly unexplained and arbitrary change based on the President's personal views and, potentially, personal investments," the Standing Rock Sioux Tribe said Tuesday.

The tribe and its allies have protested in North Dakota for months, blocking the path of the pipeline during peaceful demonstrations and clashes that have sometimes turned violent.

Last week, despite the bitter cold, about 500 protesters stood their ground. John Fixico of the Muscogee (Creek) Nation became emotional as he wondered aloud what would happen if the pipeline broke.

"Rivers are not blue anymore. They are brown and they are black. They've got droplets in it. You can't drink that," he said. "So that's why I'm here. Not only is it for the land -- to protect the land -- and for these people here. It's to help protect that water."

It's not only Native American tribes trying to stop the pipeline. Army veteran Julie Kurylowicz said she felt it was her duty "to come out here and protect these people."

"This is the front line of the war between the people and those who wish to oppress us and exploit our lands for profit, and we're are not going to back down," she said.

Pipeline supporters: This is a good investment

The pipeline's developer, Energy Transfer Partners, and other supporters say the $3.7 billion pipeline project would be an economic boon.

The developer estimates the pipeline would bring $156 million in sales and income taxes to state and local governments and will add 8,000 to 12,000 construction jobs.

The Midwest Alliance for Infrastructure Now , which supports the pipeline, said it welcomed the news that an easement may be near.

"After nearly 1,000 days since the beginning of this process, we are hopeful that we may be one step closer to the ultimate completion of the project," spokesman Craig Stevens said in a statement.

"We appreciate that President Trump is keeping his word to move lawful, carefully sited energy projects forward. This is a positive development for the pipeline, construction workers across the country, and those who seek to invest in our nation's infrastructure."

New hopes for Keystone?

Like Dakota Access, the Keystone XL Pipeline had been the subject of environmental concern from activists, residents and indigenous tribes who worried that the pipeline would pollute as many as 2,500 aquifers.

But pipeline supporters touted the jobs it would create and other economic benefits.

The $8 billion Keystone XL Pipeline was proposed to stretch nearly 1,200 miles across six states, shuttling carbon-heavy petroleum from Canada to the Gulf Coast.

In November 2015, President Obama nixed the proposed pipeline, virtually ending the fight over the project that had gone on for much of his presidency.

But Trump's executive actions on both pipelines signal how his administration will take a different approach to energy and environmental issues.