SALEM — The Trump administration is neglecting the U.S. government's obligation to build new homes for Indians whose original abodes were submerged by dams along the Columbia River, members of Congressional delegations from Oregon and Washington state said.

The hundreds of tribal members are living in dilapidated trailers and other substandard housing along the Columbia River. The promised new homes haven't been built yet even though decades have passed since the dams were built. Now a funding decision by the White House's Office of Management and Budget has put even the preparation work on hold.

In a letter, the politicians told Mick Mulvaney, director Office of Management and Budget, that "the federal government has a legal and moral responsibility" to maintain the funding. They urged him to reconsider his decision.

The letter, dated Friday and released to the media on Monday, was signed by Sens. Patty Murray and Maria Cantwell of Washington, Sens. Jeff Merkley and Ron Wyden of Oregon, and Rep. Earl Blumenauer of Oregon. All of the lawmakers are Democrats.

When the dams were built, starting with the Bonneville Dam in 1938 and then hydroelectric dams in the 1970s, the U.S. Army Corps of Engineers agreed to relocate, replace or otherwise mitigate for losses of home and villages that became buried by water, said Charles Hudson, who works with an agency of the four Columbia River Treaty tribes.

The Indians and their ancestors had pulled salmon and other fish from the river for thousands of years, Hudson said. Not only did the dams submerge their homes and villages, they eliminated the waterfalls and rapids that were trusted fishing spots where the salmon congregated before leaping upstream.

Even after the dams appeared, backing up the river and creating large pools, many families stayed along the banks because fishing was their traditional custom and livelihood. They moved into trailers and other makeshift housing on plots of federal land, where they were told to wait for the promised new housing, Hudson said.

"No shovels have turned yet," Hudson said. "Here we are 50, almost 60 years later, and they are still waiting."

The U.S. Army Corps of Engineers, which operates and maintains 700 dams in America, had recommended roughly $3 million be spent on planning for the new villages, like conducting archaeological assessments and site evaluations, and had received about half the funds in the 2017 budget cycle, Hudson said.

But an Oct. 24 letter from the Corps cited by the five politicians said most of an estimated $1.5 million has been spent, and that future work "will cease until the remaining funds are received."

The members of Congress said they understood that Mulvaney had denied a request by the Corps to shift funding to provide that remaining $1.5 million.

"We have seen first-hand the cramped, outdated, makeshift housing with limited access to reliable utilities and restrooms that tribal members are living in today. This is a matter of public health and safety, upholding treaty rights, and requires immediate attention," the members of Congress said in their letter to Mulvaney.

The Office of Management and Budget and the White House did not immediately respond to requests for comment.

Hudson said non-Indian communities that were submerged were rebuilt by the government and have libraries and post offices.

"In comparison, the tribal communities were glaringly neglected," said Hudson, who is with the Columbia River Inter-Tribal Fish Commission.