Our Data & Methodology

Transparency is non-negotiable. Here's where every number comes from.

Data Sources

NPS API

The National Park Service API provides baseline park information: descriptions, GPS coordinates, campground details, activity listings, and accessibility data. We pull this data programmatically and store it locally.

IRMA Visitor Statistics

Monthly and annual visitation numbers come from the NPS Integrated Resource Management Applications (IRMA) portal. We use 2020–2024 data to calculate trends, seasonal patterns, and peak/trough ratios.

Climate & Weather Data

Monthly average temperatures and precipitation data are sourced from NOAA climate normals and supplemented with park-specific weather stations where available.

Key Metrics Explained

Congestion Index (1–10)

A composite score measuring how crowded a park feels. Inputs include visitors per trail mile, visitors per square mile, campsite pressure (visitors per campsite), and seasonal concentration. A score of 1 means near-total solitude; 10 means peak-season gridlock.

Monthly Visit Score

Combines weather comfort (temperature, precipitation) with crowd levels for each month. A high score means good weather and manageable crowds — the sweet spot for visiting. Scores account for seasonal closures and accessibility.

Hidden Gem Index

Measures how underrated a park is relative to its quality. Parks with high activity quality scores but low visitor numbers rank as hidden gems. Yellowstone (great but crowded) scores low; North Cascades (great but empty) scores high.

Campsite Pressure

Annual visitors divided by total campsites. A high number means heavy competition for camping spots, suggesting you should book months in advance or consider alternatives.

Trip Cost Estimate

A basic 2-night camping trip cost calculated from entrance fee + 2 nights of camping (~$30/night average) + round-trip gas from the nearest major city (at $3.50/gallon, 25 MPG). This is a floor estimate — lodging, food, and gear costs are not included.

Limitations

  • Visitation data lags: The most recent complete data is from 2024. Actual 2026 conditions may differ.
  • NPS counts vary: Different parks count visitors differently (some at gates, some via trail counters). Cross-park comparisons have inherent imprecision.
  • Crowd level is a proxy: Our congestion index captures relative crowding but can't account for specific trailhead conditions on a given Tuesday.
  • Weather is averages: Monthly temperature and precipitation data represent 30-year normals, not forecasts. Always check conditions before your trip.
  • Subjectivity in quality scores: Activity quality ratings (1-10) involve editorial judgment informed by data but not purely algorithmic.

Updates

We update visitation data annually when new IRMA numbers are released. Park details (campgrounds, trails, fees) are refreshed quarterly via the NPS API. If you notice outdated information, please let us know.