NPS publishes the historic site list through the same API that covers all park units, with a unit_type field that filters to national historic site. A scheduled job pulls the API, joins it with a curated era and theme dictionary, and writes one JSON row per site for the page group to read.

Add a row to the roster with the establishment year, the era, the theme, the key figure if applicable, and the canonical NPS URL. The cache refresh stamps a new live URL on the next render and the sitemap regenerator picks it up within hours of the establishment.

Carry a hours array per site with season label, days open, and hours. The page renders the schedule as a small grid with the current season highlighted. Seasonal closures and reduced winter hours are common across the system, so the structured grid avoids confusion.

Yes. Carry an education_materials array per site with title, grade level, format, and download URL. The page renders the materials as a sidebar block aimed at teachers planning a field trip. Many sites publish robust materials but bury them on a sub-page.

Sites like Sagamore Hill or Lincoln Home preserve multiple structures with separate access rules. Carry a structures array per site with name, type, access status, and tour requirement. The page renders the structures as a grid and the tour requirements as callouts.

Yes. The theme field drives a related-sites block at the bottom of the page that surfaces other units in the system covering the same theme. A Reconstruction site links to other Reconstruction sites and the block is automatic from the curated theme dictionary.

Yes through a deep link block. The NPS app supports deep links to a site by unit code, and the page carries a unit_code field that drives the deep link button. Visitors who plan their trip on the website can hand off to the app for offline maps and audio tours.

A few historic sites have changed designations over the decades, for instance from historic site to national park. Carry a designation_history array with year and designation type. The page renders the history in the sidebar so the reader understands the current status.