Starting in 1996, Alexa Internet has been donating their crawl data to the Internet Archive. Flowing in every day, these data are added to the Wayback Machine after an embargo period.
Crawl DX from Alexa Internet. This data is currently not publicly accessible.
TIMESTAMPS
The Wayback Machine - https://web.archive.org/web/20040606195612/http://tps.cr.nps.gov:80/nhl/default.cfm
* PRIORITY
Emergency indicates that recent catastrophic damage has occurred that requires immediate intervention. Threatened (Priority 1) indicates NHLs that have suffered, or are in imminent danger of, a severe loss of integrity. Watch (Priority 2) indicates NHLs that face impending actions or circumstances that likely will cause a loss of integrity. A blank field (Priority 3) indicates there is no known current or potential threat to the landmark.