Potential Adjustment to the Visitation Calculation Method Coming for Acadia


Current data indicates Acadia had about 3,970,201 visits in 2022. Not VISITORS as in people, but visits.

So: What Constitutes a “Park Visit”?

The National Park Service (NPS) Visitor Use Statistics program defines a visit as, “The entry of a person onto lands or waters administered by the NPS except for non-reportable and non-recreation visits… The applicable rule is that one entrance per individual per day may be counted.” Reentries on the same day, as well as entries to a detached portion on the same day, are considered a single visit, meaning there were about 3,970,201 entries or visits to Acadia for 2022.

Counting Challenges

For anyone with a cursory knowledge of Acadia, counting park visits appears problematic. There are really only two formalized entrances (the Sand Beach entrance station and the Cadillac Mountain entrance station) where a visitor might encounter a ranger, pay the necessary fee, and obtain a map and park information.

For better or worse, visitors can and often do enter and exit the park multiple times a day and have no idea they are doing so. How do we keep track of all these entries and exits to count visitation then? Well, the secret is, we don’t. Visitation to Acadia National Park is not a count, it is a calculation; an estimate if you prefer. But it is not one we take lightly. A great deal of work and effort goes into making sure we get it right.

Revisiting Counting Methodology

Acadia National Park has visitation records going back to 1919 when Acadia was still known as Lafayette National Park (the renaming to Acadia came in 1929). Approximately 64,000 people visited that year and more than 12 times that many visited in July 2022.

The first record of a formalized visitation calculation method for Acadia came in 1960. At that time, traffic counters on Thompson Island and elsewhere were used to estimate park visitation though the use of multipliers. A similar method was used through 1989 with a revision taking place in 1971. By 1989 the counter at Thompson Island was no longer deemed reliable for estimating visitation to the park (1989 visitation was estimated at 5,440,952).

In 1990, researchers from the University of Vermont (Dr. Robert Manning and others) helped to dramatically alter the visitation calculation method. The focus shifted from Thompson Island to the Sand Beach entrance station. After an exhaustive study of visitors using interviews and surveys, the research team developed a set of monthly multipliers that represented the relationship between entries at the Sand Beach entrance station and entries to the remainder of the park on Mount Desert Island (Schoodic and Isle au Haut were treated separately).

In other words, they determined that for every car entering the Sand Beach entrance, there were, depending on the season, between two and four other cars entering the rest of the park on Mount Desert Island.

The 1990 visitation calculation method received slight adjustments every few years, but being more than 30 years old, it was overdue for a critical review. In 2021 Acadia National Park contracted with an outside consultant to replicate the 1990 visitation calculation method using modern visitor use modeling technology (Bluetooth and Wi-Fi with GIS modeling and analysis) to determine whether the current counting method was still valid.

Furthermore, we wanted to know how the calculation might need to be adjusted.

Results from the study were finalized in 2022 and are still being reviewed internally, but surprisingly the changes suggested by the research group would result in past visitation estimates that differ by less than 4 percent of overall visitation estimates.

This is a shocking result considering the analog methods used to create the 1990 method compared to the tracking and modeling technology used in the study. Considering the similarity in the estimates, the park will need to determine the value of adjusting the current calculation method.

The purpose of tracking visitor use statistics is to prove a statistically valid, reliable, and replicable method for collecting and reporting visitor use data for the park, and Acadia works hard to support regular data collection, timely publication, and interpretation of these data.

We also enact regular quality control checks to ensure consistency and comparability of the data to compare to previous years and among other NPS units.

Deciding to revisit a 30-year-old visitation calculation method was an easy decision to make, and the fact that it’s held up so well all these years indicates both the quality of the original work and the consistency of visitor behavior.

Dive Deep Into Visitor Use Statistics

If you would like to know exactly how Acadia or any NPS unit calculates visitation, you can do so by visiting the Integrated Resource Management Applications (IRMA) portal
at irma.nps.gov. Here you will find not only visitor use statics for every NPS unit and how they were calculated, but a treasure trove of NPS research and data.

2022 Visitation Second Highest on Record for Acadia

How did we get here and where are we headed?

Learn More

DR. ADAM GIBSON manages the Social Science program at
Acadia National Park.