Julia Trigg Crawford scours her land for Indian artifacts (she found some arrow heads and shards of pottery). The sacredness of the land is one of the reasons that she does not want the pipeline to run through her property. (Michael S. Williamson/THE WASHINGTON POST)

A judge in Lamar County, Texas, ruled Wednesday night that TransCanada’s Keystone XL pipeline has the right of eminent domain, rejecting a plea by farm manager Julia Trigg Crawford and dealing a blow to landowners and environmentalists who have been trying to block construction of the pipeline.

The ruling by Judge Bill Harris removes yet another potential obstacle for TransCanada, which already has permits from the Army Corps of Engineers for the southern leg of the pipeline, which starts in Cushing, Okla., and runs to Port Arthur, Texas. TransCanada has said it will start building as soon as possible.

In March, President Obama endorsed the construction of the southern leg of the pipeline. He said it would alleviate a supply bottleneck at Cushing, where the benchmark price of oil is set for the U.S. market.

But environmental groups and some landowners have been mounting a campaign to stop or delay construction because of the threat a leak might pose to rivers and wetlands.

Crawford had asserted that the Keystone XL pipeline was not entitled to eminent domain because the pipeline would not be a common carrier, open to a variety of oil companies. She said that as a private project, it needed to negotiate rights of way without compelling landowners to enter agreements.

Usually the option of using eminent domain for pipelines is granted by state agencies; in Texas, it is recognized by the Texas Railroad Commission, a long-time regulator of the state oil industry.

Eminent domain is a touchy topic in Texas. In 2002, Gov. Rick Perry proposed a Trans-Texas Corridor, a private sector network of highways. The main artery would be a 600-mile road running from Mexico to the Red River that would be the width of four football fields. After an outcry about the seizure of private land — and increased traffic from Mexico — the state transportation department killed the idea.

“Of course we are incredibly disappointed in today’s ruling,” Crawford said in an e-mail late Wednesday night. “Disheartened that Texas landowners must still challenge oil corporations in court on what should be State-level permitting issues .... and disturbed that a foreign corporation like TransCanada is allowed to hide behind the skirt of the Texas Railroad Commission and its Common Carrier rubber stamp.”

Jane Kleeb, an activist with the group Bold Nebraska who has been fighting the pipeline’s eminent domain status, said in an e-mail Wednesday night that “A foreign oil company — exporting a form of energy that our government is still studying and the Canadian government just issued a safety violation on — gets to seize American land without proving they are a common carrier and without any requirement that Americans get a drop of the oil. There is something wrong with this picture.”