Historic Entrance to Mammoth Cave Photo: Warren LeMay / Wikimedia Commons (CC BY-SA 2.0)
All Parks
Kentucky · Est. 1941
Park Map PDF

Mammoth Cave

The longest known cave system on Earth — over 420 surveyed miles and counting, beneath rolling Kentucky hill country and the Green River.

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🕳️
420+ miles
Longest cave on Earth
💵
$0
Surface entrance fee
🎟️
$12–$79
Cave tour tickets
💧
Live
Green River gauge
🏕
$20–$25
Campground/night
🌡️
54°F
Year-round cave temp
⚠️Cave & Trail SafetyUneven, wet trails▾
🕳️ Cave trails are uneven, often wet, and pass through sections with low ceilings and dim lighting — use handrails and stay on marked paths. Cave temperature holds steady at 54°F year-round, so bring a light jacket even in summer. On the surface, watch for ticks, poison ivy, and venomous copperheads and rattlesnakes along trails and near the Green River. Summer heat can exceed 90°F — carry water on any outdoor hike. Children under 16 must be supervised at all times on tours. NPS safety info ↗
🎟️Cave Tours & ReservationsBook ahead▾
📅 The surface and visitor center are free, but every cave tour requires a paid, timed ticket — advance reservations via Recreation.gov are strongly recommended, since popular tours sell out, especially in summer and around holidays. Ranger-led tours range from easy walk-throughs to strenuous crawling routes. NPS tour guide ↗
Tour Options$12 – $79▾
Discovery TourSelf-guided, shortest and easiest — $12
Mammoth Passage TourRanger-led, beginner-friendly — $15
Historic Tour2 miles through the original 1816 route — $24
Grand Avenue Tour4-mile, most extensive route offered — $42
Wild Cave TourStrenuous crawling/caving, age 16+ — $79
💧Green RiverLive USGS gauge▾
USGS Site 03309000 — Green River at Mammoth Cave, KY
Streamflow -- ft³/s
Gauge Height -- ft
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The Green River carved much of the cave system and still floods parts of the lower passages during high water. Full USGS station data ↗
🏕Camping3 campgrounds▾
Mammoth Cave CampgroundReservation▾
LocationNear the visitor center
Fee$25/night ($12.50 accessible/senior)
Houchin Ferry CampgroundReservation▾
LocationOn the Green River, quieter/remote
Fee$20/night ($10 accessible/senior)
Maple Springs Group CampgroundGroups only▾
Fee$50/night per group site
Full camping details on NPS.gov ↗
Park Contact Information
📞 Phone: (270) 758-2180  ·  Mailing Address: 1 Mammoth Cave Parkway, Mammoth Cave, KY 42259  ·  Official NPS contact page ↗