INDIAN ISLAND, Maine — The Penobscot Indian Nation has endorsed a proposed 150,000-acre national park and recreation area, saying the parks would protect the Penobscot River and associated waterways much the way the tribe has “since time immemorial.”

Nation President Kirk E. Francis called upon U.S. Sens. Susan Collins, R-Maine, and Angus King, I-Maine, to introduce a bill to Congress supporting the creation of the park and recreation area.

“Residents of the Katahdin region and tribal members alike would benefit, not only from the long-term protection of the lands surrounding the rivers, but also from the economic activity that a new national park and national recreation area would bring to the greater Bangor and Katahdin regions,” Francis said in a statement released earlier this week.

“Visitors coming to Acadia [National Park] would have a reason to spend a few extra days to go explore the new national park and national recreation area in the Katahdin region,” Francis added. “They could fish, camp, hunt, watch birds and other wildlife, snowmobile and see spectacular views of Katahdin.”

Francis and leading park advocate Lucas St. Clair, entrepreneur Roxanne Quimby’s son, did not immediately return telephone or email messages left Thursday. Nor did a spokesman for the Quimby family foundation, Ian Grady.

Quimby and her son St. Clair in 2011 proposed creating a 75,000-acre national park and nearby 75,000-acre multiuse recreation area. The park and recreation area would be located on Quimby lands east of Baxter State Park. The family’s foundation proposes to create a $20 million endowment and raise another $20 million to fund park maintenance.

Attempts to reach the spokespersons for Collins and King were not immediately successful on Thursday.

The Indian nation is the first group to publicly endorse a park since the last election, in which four of 11 East Millinocket and Millinocket candidates for public office said they favored the park for what they said would be its positive impact on the Katahdin region’s economy, which had its mills’ last two paper machines shut down in 2008 and 2013. Two of the four, East Millinocket Selectman Mark Scally and Millinocket Town Councilor Anita Mueller, were elected.

The Katahdin Area Chamber of Commerce and several environmental groups endorsed the idea, but East Millinocket and Millinocket governments and residents have staunchly opposed the proposed park. Officials in Medway, which elects its selectmen during town meetings in the spring, have said they favor a park feasibility study. An independent committee of town officials and residents formed to support the study but later withdrew its support.

Opposition to the park remains daunting. The Penobscot County Board of Commissioners, Gov. Paul LePage, the Maine Legislature, gubernatorial candidate and U.S. Rep. Mike Michaud and Collins have opposed the park. King told the New York Times that he was “opposed and skeptical but listening.” East Millinocket residents voted 513-132 in 2011 against a feasibility study of the park.

Francis said that about 25 miles of the East Branch of the Penobscot River would flow through park lands, as would several associated streams. A bill offered by a member of Maine’s federal delegation would be a crucial element to the creation of a park.

The bill would have to pass in the House of Representatives and the U.S. Senate and be signed into law by President Obama before a park could be created.