The documents, which include the paper designating the area as a national park in 1953, have been handed county record office in Northallerton for archiving.
National park authority chief executive David Butterworth said: “These archives form part of the history of this beautiful national park and, in their own way, they are a priceless record of how an area of the countryside was identified as being special and how an incredible amount of work was put into ensuring it was protected and enhanced for future generations.
“There are hundreds of documents containing agenda papers and correspondence between Whitehall and local councils to thrash out the nitty-gritty detail of what the national park should be responsible for, what area it should cover and how it should function.
“And it’s appropriate that these documents should be highlighted now as preparations are being made for a public inquiry to decide on a Natural England proposal to expand the boundaries of the Yorkshire Dales and the Lake District National Parks.”
County council archives development manager Keith Sweetmore said: “The archives will be permanently stored here in safe conditions and they will be made available to anyone interested in the early history of the national park.
"The papers will be joining a large number of documents relating to the history of North Yorkshire and will help to build up a more detailed picture of its past.”