Forty-six years of National Park Service visitor-use data, read by month, by park, and by the shoulder windows that actually thin the trails.
The three units travelers Google most. Each card reads against its own twelve-month curve. Rust marks the peak. Ochre marks the floor.
Late May, mid-September after Labor Day
Late May for waterfalls, October for color
Late March to mid-May, October
Top ten units, ranked by recreation visits. Sparklines normalised to each park's own peak — taller bar, busier month.
| # | Unit | State | Twelve-month curve | Peak | Quiet | Spread | Annual |
|---|---|---|---|---|---|---|---|
| 01 | Great Smoky MountainsGRSM · National Park | TN / NC |
|
Jul | Jan | 4× | 12.19M |
| 02 | Grand CanyonGRCA · National Park | Arizona |
|
Jul | Jan | 3× | 4.73M |
| 03 | ZionZION · National Park | Utah |
|
Jul | Jan | 4× | 4.62M |
| 04 | Rocky MountainROMO · National Park | Colorado |
|
Jul | Feb | 7× | 4.15M |
| 05 | YosemiteYOSE · National Park | California |
|
Jul | Jan | 5× | 3.90M |
| 06 | YellowstoneYELL · National Park | WY / MT / ID |
|
Jul | Feb | 25× | 4.50M |
| 07 | AcadiaACAD · National Park | Maine |
|
Aug | Jan | 15× | 3.96M |
| 08 | OlympicOLYM · National Park | Washington |
|
Jul | Jan | 7× | 2.95M |
| 09 | GlacierGLAC · National Park | Montana |
|
Jul | Jan | 29× | 2.91M |
| 10 | Joshua TreeJOTR · National Park | California |
|
Mar | Aug | 3× | 2.54M |
A flat-stock calendar of the park to point at when the dates are already locked. Designation accurate, planning honest.
Each cell shows what share of the park's busiest month that month carries. Rust runs hot. Cream runs quiet. Read across to find the gap.
Four shoulder windows where the data disagrees with the holiday calendar. Higher score, thinner crowds — graded against each park's own peak month.
Aspens turn, elk bugle starts, full operations. Timed-entry permits expire mid-October.
Vehicle reservation window ends. Going-to-the-Sun open. Larch needles turn gold weeks later.
Counter-cyclical desert park. Spring is the crowd peak. Late autumn delivers cool days, dark skies.
Before the shuttle queue starts. The Watchman trail and Pa'rus walk open and uncrowded.
Most travel sites tell you to visit Yellowstone in summer. The data tells you when summer breaks — and that's the part worth reading. We turn the National Park Service's own forty-six-year visitor-use record into crowd timing, seasonality, and shoulder windows worth knowing.
Every page here is built on the official NPS Visitor Use Statistics Data Package, 2025 — the same dataset the agency itself uses. Monthly averages smooth across five reporting years. Crowd scores are percentile against each park's own twelve-month distribution, not against other parks.
We use "NPS sites" or "National Park Service sites" when covering all unit types, and "National Parks" only for units that officially carry that designation. We don't use the NPS Arrowhead. We're not official. We're the people who read the chart so you don't have to.
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