Boston Harbor Islands National Recreation Area

SOURCES & DEFINITIONS

Know what the map counts.

Source: National Park Service API for sites, facilities, campground locations and published fee entries; NPS Public Use Statistics for monthly recreation visits, 1979–2025. Snapshot retrieved 2026-10-03. 474 NPS site records include 62 national-park API records; Sequoia and Kings Canyon share one API record. These record counts are not the official count of individually designated parks. 392 API site records have matched visitation history, including the separately reported Sequoia and Kings Canyon visit totals combined for their shared API record. 665 campgrounds are included.

Complete monthly series reconcile with the source’s annual totals. Published annual totals remain available for years with partial monthly reporting. Four monthly entries contain negative accounting corrections. They remain in the archived data and annual totals, and are unavailable as ordinary monthly visit counts. Blank data is not zero. Recreation visits are visits, not unique people. Month as percent of annual peak = selected month visits ÷ largest monthly count that year × 100, requiring twelve nonnegative monthly values. This helps compare recorded seasonality; it is not a crowding forecast, reservation forecast, or present-condition report.

Activities and amenities reflect published NPS entries, rather than a guarantee of access on a particular day. Fees and pass categories are dated 2026-10-03; official site and reservation links provide current conditions and rules. Campground points are published NPS coordinates. Offshore sites can be viewed on the world extent. Broader public-land agencies are outside this reviewed NPS snapshot.

World outlines: Natural Earth 1:50m map units, public domain. U.S. state outlines: Census via us-atlas. Source licenses apply to their respective inputs and derived data. Download the derived parks snapshot · Source manifest, retrieval dates and SHA-256 hashes.