The largest projects:
- $44m to build a memorial to United Flight 93, the hijacked plane that passengers brought down before it could reach its target (presumably the White House or U.S. Capitol)
- $26m for a new visitor center for Old Faithful in Yellowstone NP
- $24m to replace the visitor center and HQ at the USS Arizona Memorial in Pearl Harbor HI
- $20m for restoration of disturbed lands in the Everglades
Items of that size are the exception; the vast majority of these 200+ projects carry six- or even five-figure price tags. More information on the Park Service's Centennial Initiative at this link.