Grand Avenue Tour, Mammoth Cave National Park - Kentucky, United States

The Grand Avenue Tour is the longest hiking tour offered by the Mammoth Cave National Park.  It takes about 4 ½ hours to hike 4 miles inside the cave.  The park classifies this hike as “Physically Demanding” but in fact, the ranger led us at a slow pace and there were a lot of rest stops including lunch breaks and washroom breaks to accommodate everybody.  Yes, lunch at a cafeteria inside the cave at 267 feet below surface where you can buy a boxed sandwich for $7.50 exact change.  There were two washrooms where the park uses electric pump to pump human waste back up to the ground level.

After finishing a demanding spelunking tour yesterday, I found this hike extremely easy.  The same ranger who led us in the spelunking tour was leading us again this time.  She was so agile yesterday demonstrating us how to climb up and slide down some dangerous cliffs to avoid falling.  Today in a totally opposite manner, she walked very slowly especially for the first flat 2 miles.  I found the crawling yesterday was even faster than the walking today.  Again, As there was no GPS detection underground,  I'm just measuring an approximate trace following the highway . 

We entered the cave from the Carmichael Entrance and hiked 4 miles ending at the Frozen Niagara Entrance.  Started hiking in the Rocky Mountain through the Cleveland Ave and entered the Snowball Room where we had lunch and pit stop, 267 ft underground.  We then entered  Mary’s Vineyard where we could see cave formations in the shape of grapes on the wall.  The path then narrowed, leading to Boone Ave; it reminded me of a similar stone texture in the Mosaic Canyon in Death Valley, only that here, it is underground in the cave.

The last section was somewhat hilly, with steep up and downs, at 195 feet underground.  Some sections were steep descent and slippery and we were asked by the ranger to hold on the rail to come down slowly. There was another washroom stop before coming to the Grand Canyon where there were deep cliffs on either side of the trail.  Here we saw numerous columns formed by the unions of stalagmites (growing upward from the ground) and stalactites (goiwing downward from the ceiling).  The last section was the Frozen Niagara at 130 feet underground.  We ended the hike and exit at the Frozen Niagara exit.

The entire 4-mile hike started from the Carmichael Entrance ending at the Frozen Niagara.  During the tour, we learned the interwoven natural and cultural history and hike through some of the most dramatic passages of Mammoth Cave.  We walked through gypsum lined passages, narrow canyons, undergound hills, steep uphill and downhills, large rooms and area with dripstone formations.  We saw gypsum and different kinds of colonial corals, but the experience were not as dramatic as what's in the spelending tour yesterday.  As we crawled through some very narrow passages yesterday while maintaining balance along the undergrond water streams, we were not to touch the gypsum and the corals while going through tight spces. Since these formation takes 100 years to grow just the length of a fingernail, we wouldn't want to touch the walls to damage these treasures.


I believe we could have started from the Historic Entrance at the Visitor Centre all the way to the Frozen Niagara, except we might have to swim part of the trail underground on Lake Lethe and Echo River, 360 feet below surface, which would be cool if the park allows this kind of hike!