Trail Mix data and methodology
Where Trail Mix park data comes from: NPS visitor statistics, official park boundaries and designation dates.
Where the numbers come from
Every figure in Trail Mix comes from data the National Park Service publishes itself. Visitor counts are the sum of a park’s twelve monthly recreation visits for 2025, from NPS IRMA (Integrated Resource Management Applications) Visitor Use Statistics. A recreation visit counts one person entering a park for recreation, so a visitor who leaves and comes back later the same trip can be counted more than once — it measures visits, not distinct people. Area is measured from the official boundary polygons the NPS Land Resources Division maintains for every unit, projected into an equal-area coordinate system so acreage compares fairly across a list that runs from a few hundred acres to several million. Location is the centroid of that same boundary, and every distance Trail Mix shows is the great-circle distance in miles between two parks’ centroids.
How each field is defined
| Field | Definition |
|---|---|
| Distance | Great-circle miles between the guess and the answer, measured centroid to centroid. |
| State | Every postal state or territory code the park’s boundary sits in, primary state first. |
| Established | The year the place became a national park under that exact designation. |
| Area | Acres inside the whole unit’s official boundary, including any attached national preserve. |
| Visitors | Recreation visits recorded for 2025, summed from monthly NPS figures. |
What “established” means
The established date is the day a place became a national park by that exact designation, not an earlier protection or a later boundary change. Guadalupe Mountains, for instance, is dated to 1972, when Congress created the national park, rather than 1966, when it first authorized buying the land.
Why acreage can look different elsewhere
Because area comes from the whole unit’s official boundary rather than a published acreage table, Trail Mix’s figures can differ from the gross acreage the NPS reports elsewhere. Several parks fold in an attached national preserve inside a single boundary — Denali, Gates of the Arctic, Glacier Bay, Katmai, Lake Clark, Wrangell–St. Elias, Great Sand Dunes and New River Gorge among them — and a handful of boundaries reach past dry land entirely, as American Samoa’s does into surrounding ocean waters. How far a park’s figure drifts from other published totals varies a great deal from park to park, so we don’t claim a single percentage; every park in the game is measured the same way, from the same boundary source.
Which parks and years are covered
Trail Mix covers all 63 places carrying the “national park” designation itself — not national monuments, national preserves standing alone, national historic sites or any other unit type the National Park Service manages. Visitor totals cover 2025, the most recent full year available when this dataset was built.
Updates and fairness
The park chosen for a published puzzle never changes, but its figures may be refreshed when the dataset updates. NPS publishes a new year of visitor totals once annually, and Trail Mix’s data refreshes on that same yearly cycle. If a correction is needed for a park that appears in a future puzzle, the change is made before that day. To report a data problem, email hello@guessday.com with the puzzle number.
Attribution and independence
Visitor, boundary and designation data come from the National Park Service, part of the U.S. Department of the Interior, and are works of the United States government. Trail Mix is not affiliated with the National Park Service. Park names identify the places described and remain the property of the National Park Service; nothing on this site is official NPS guidance.