TULSA, Okla. (AP) — The U.S. Army Corps of Engineers in Tulsa has approved a segment of TransCanada Corp.'s Keystone XL pipeline planned to run from Cushing to Texas.

Ross Adkins, chief of public affairs for the Tulsa district, confirmed the decision Friday. If the overall project is approved by the president, the pipeline could eventually transport tar sands oil from western Canada to refineries along the Texas Gulf Coast.

TransCanada needs corps approval for its wetlands and water-crossing plans. The company awaits a similar decision from the corps' Fort Worth, Texas district.

The Obama administration shelved the project earlier this year, explaining that officials needed more time to study alternate routes that would bypass certain environmentally sensitive areas in Nebraska.

Earlier this month, the U.S. State Department announced that it would issue a final decision on the project early next year.

Russ Girling, TransCanada's president and chief executive officer, has said by the time the final decision is made on the pipeline, "Keystone XL will be well into its fifth year of exhaustive and detailed studies, the most extensive review for a cross-border pipeline ever."

"The final review should focus solely on the realigned route that avoids the Nebraska Sandhills," Girling said earlier this month. "The rest of the Keystone XL route remains the same. The geology of the route remains the same. The environmental conditions remain the same. Nothing else has changed since the (Final Environmental Impact Statement) was approved."

The pipeline has drawn fierce opposition from environmental groups such as the Sierra Club, which said the $5.3 billion pipeline is a natural disaster waiting to happen if a section were to leak and threaten the drinking water supply for millions of Americans.

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  • <em>From Getty:</em> SAN FRANCISCO, CA - OCTOBER 25: Protestors against the construction of the Keystone XL oil pipeline hold signs and stand on a Keith Haring sculpture as they demonstrate outside of the W Hotel before the arrival of U.S. President Barack Obama on October 25, 2011 in San Francisco, California. Hundreds of protestors from a wide variety of activist groups staged protests outside of the W Hotel where President Obama was holding a $7,500 per person fundraiser. (Photo by Justin Sullivan/Getty Images)

  • <em>From Getty:</em> SAN FRANCISCO, CA - OCTOBER 25: A protestor against the construction of the Keystone XL oil pipeline climbs on a Keith Haring sculpture as he demonstrates outside of the W Hotel where U.S. President Barack Obama was holding a fundraiser on October 25, 2011 in San Francisco, California. Hundreds of protestors from a wide variety of activist groups staged protests outside of the W Hotel where President Obama was holding a $7,500 per person fundraiser. (Photo by Justin Sullivan/Getty Images)

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. (Photo credit should read KAREN BLEIER/AFP/Getty Images)

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. (Photo credit should read KAREN BLEIER/AFP/Getty Images)

  • <em>From Getty:</em> A demonstrator waves signs in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator dressed as an oil soaked bird in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators listen to speakers in Lafayette Park across from the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator holds signs in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A demonstrator holds a magazine open to an article concerning tanker routes for the proposed Keystone XL Pipeline in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Children demonstrate in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. AFP PHOTO / Karen BLEIER

  • <em>From Getty:</em> Demonstrators hold up a banner in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline. AFP PHOTO / Karen BLEIER

  • <em>From Getty:</em> Demonstrators begin to line up around the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> Demonstrators line up in front of the White House in Washington, DC November 6, 2011. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>From Getty:</em> A sign is seen in Lafayette Park across from the White House in Washington, DC November 6, 2011 during a protest. Thousands of people are descending on the White House to join hands with one another and stand up to the Keystone XL pipeline.

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320235175/in/set-72157628079975942" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320925438/in/set-72157628079975942" target="_hplink">Emma Cassidy and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320975886/in/set-72157628079975942" target="_hplink">Shadia Fayne Wood and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320307073/in/set-72157628079975942" target="_hplink">Amy Dewan and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320919878/in/set-72157628079975942" target="_hplink">Emma Cassidy and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6320760272/in/set-72157628079975942" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/6321050482/in/set-72157628079975942/" target="_hplink">Clayton Conn and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/mothernature/6306631974/" target="_hplink">mothernature photography</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>

  • <em>Flickr image courtesy of <a href="http://www.flickr.com/photos/tarsandsaction/" target="_hplink">Josh Lopez and Tar Sands Action</a>.</em>