WASHINGTON (Reuters) - Montana lawmakers representing Native American tribal members called on the state’s congressional delegation and the U.S. State Department on Thursday to extend the public comment period for the environmental review of the Keystone XL pipeline, saying tribes were not properly consulted.

FILE PHOTO: Oil spilled from a section of the Keystone pipeline is seen in Walsh County, North Dakota, U.S., November 8, 2019. REUTERS/DroneBase

“We are particularly concerned with the lack of formal consultation with tribal governments whose natural and cultural resources could be significantly impacted,” the 10 members of the State-Tribal Relations committee wrote to Democratic U.S. Senator Jon Tester, Republican Senator Steve Daines and Republican Representative Greg Gianforte.

The letter called for the Trump administration to conduct a “more rigorous and meaningful public comment process” for its draft supplemental environmental impact statement of Keystone XI’s proposed route through northeastern Montana, whose public comment period closes on Monday.

The long-pending pipeline would carry heavy crude oil to Steele City, Nebraska, from Canada’s oil sands in Alberta, but has faced legal challenges from landowners, tribes and environmentalists.

A federal judge in Montana in August 2018 ordered the State Department to do a full environmental review of a revised route for the Keystone XL oil pipeline. He said the previous environmental analysis fell short of the “hard look” at the cumulative effects of greenhouse gas emissions and the impact on Native American land resources that was required.

The environmental impact statement will be the basis for other federal agencies to issue construction permits for construction, including one by the Army Corps of Engineers to allow the proposed line to be built under the Missouri River.

Members of the Fort Peck Reservation are concerned that the pipeline would sit beneath the spillway of the Fort Peck dam, which would make it vulnerable to the velocity of water discharge from the dam.

Democratic state Senator Frank Smith, a tribal member on the committee who represents a district on Fort Peck, said tribal members were worried that recent spills on TC's original Keystone Pipeline here in neighboring North Dakota could happen on their land and harm their water.

He said the Fort Belknap Indian Community and the Fort Peck Tribes were not given the chance to formally consult the State Department and air their concerns.

“TC Energy has a history of leaky pipelines. I don’t think their precautions are as good as they say they are,” Smith told Reuters.

TC Energy Corp and the State Department were not available for comment.