Two National Parks · 311 miles apart
Mammoth Cave or Indiana Dunes
Indiana Dunes drew 2,629,497 recreation visits in 2025, 4.0 times the 660,734 at Mammoth Cave, so crowds are the largest difference. Mammoth Cave charges no entrance fee while Indiana Dunes charges $25 per private vehicle. Mammoth Cave holds an International Dark Sky designation and Indiana Dunes does not. On the rest they match, since neither uses timed entry. The two parks are 311 miles apart in a straight line.
| Mammoth Cave National Park | Indiana Dunes National Park | |
|---|---|---|
| Designation | National Park | National Park |
| States | Kentucky | Indiana |
| Recreation visits, 2025 | 660,734 | 2,629,497 |
| Entrance fee, private vehicle | None, free to enter | $25 (Private Vehicle) |
| Timed entry reservation | No | No |
| Campgrounds | 3 | 3 |
| International Dark Sky Park | Yes | No |
| Bird species, NPSpecies | 168 | 301 |
| Hours or season | Open all day, every day | The general areas of the park are open year-round. |
Mammoth Cave visits by yearIndiana Dunes visits by year
Fees, hours, campgrounds and timed entry from the NPS API. Visits from the NPS Visitor Use Statistics system. Dark sky status from DarkSky International. Bird counts from the NPSpecies inventory. Data refreshed October 14, 2026. Other pairs.