National Park Service Superintendent Tyrone Brandyburg (C) and  Secretary of the Interior Ryan Zinke hold a check donated by U.S. President Donald Trump salary to the National Park Service as White House Press Secretary Sean Spicer (R) holds a daily press briefing at the White House in Washington, U.S., April 3, 2017. REUTERS/Carlos Barria - RTX33X23

Interior secretary Ryan Zinke accepts Trump's check at a White House press conference. (Reuters/Carlos Barria)

Donald Trump has a mixed record of success on his campaign promises—but April 3 marked one pledge kept: to forego a salary as US president. In a mini-presentation ceremony in a White House press conference, press secretary Sean Spicer announced Trump would donate his salary from the first quarter, totaling $78,333, to the National Park Service.

Interior secretary Ryan Zinke said he was "thrilled" by the donation and would put it toward upkeep of national battlefields, where he said his department is "about $229 million behind in deferred maintenance."

That means Trump is putting up 0.03% of what the battlefields need out of his own pocket. By contrast, he wants to cut the Department of the Interior's 2018 fiscal year budget by 11.7%, or $1.6 billion.