The tribe is sending the formal letter with notice of its opposition, said Lummi Nation Natural Resources Director Merle Jefferson. The tribe has a strong position, based on treaty rights, he said.
The Corps has refused to process permits on other projects that tribes said would violate treaties, The Bellingham Herald reported Thursday.
"If the Lummis come to that position, it will make us reassess the direction we are going," said Muffy Walker, the Corps of Engineers regulatory branch chief in Seattle. "We have denied permits in the past, based on tribal concerns."
The tribe also has submitted 34 pages of objections during the process to determine the scope of an environmental review by the corps, state Ecology Department and Whatcom County.
The tribe said the terminal would interfere with fishing and disrupt an important cultural site. Tribal officials also met on the beach at Cherry Point last September to announce their opposition.
The company planning the terminal, SSA Marine of Seattle, says it will continue to work with the Lummi tribe to resolve concerns about fishing rights and burial grounds.
"We are committed to addressing Lummi concerns in detail," SSA Marine Vice President Bob Watters said in an email. "Our approach will be first to avoid impacts, then to minimize unavoidable impacts, and finally, to mitigate and positively address what remaining impacts there may be in a mutually satisfactory way."
The project is one of three in the Northwest proposed to ship coal from Montana and Wyoming to Asia. The others are on the Columbia River at Longview and Boardman, Ore.
The Gateway Pacific proposal received another setback on Wednesday when the state Ecology Department said its two-year environmental review would go beyond state borders to consider impacts of greenhouse gases and possible climate change from burning coal at power plants in Asia.
The corps has declined such a broad review of proposed terminals and said the impacts of burning coal overseas were beyond its purview.
In another development, SSA Marine said Wednesday it has agreed to pay $1.65 million to settle a lawsuit over the company's unauthorized land clearing at Cherry Point in 2011, The Bellingham Herald reported.
RE Sources for Sustainable Communities had sued, saying the company violated the federal Clean Water Act when it built nearly five miles of roads, filling or clearing nearly three acres of wetlands in the process.
SSA Marine said it settled to avoid further costly litigation.
The company admitted it made a mistake in failing to get proper permits for clearing roadways to bring geotechnical testing equipment to its property, Watters said. It stopped work as soon as it realized the error and moved to repair the damage in cooperation with county, state and federal agencies.
The company will pay $800,000 to cover RE Sources' legal costs and $850,000 for Puget Sound environmental restoration projects.