We’re in our second week of a heat wave here in the St. Louis area, the kind that pushes the heat index well over 1oo degree Fahrenheit and keeps us all stuck inside and miserable. We’re fortunate to have air conditioning and lots of fun places to escape the heat, but one day last week, it wasn’t enough.

It was one of those rare days when neither of my children had plans with friends and both were bored and cranky. We needed to get out of the house, to someplace else cool, obviously, but the struggle of agreeing on a destination proved too much. Finally I’d had enough. I decreed that we would have a “Mom’s Choice Mandatory Fun Adventure Day,” marched them to the car, and refused to tell them where we were going.

Then I drove them an hour through winding back roads over to Interstate 44, to Meramec Caverns, the most widely toured cave in Missouri and where it’s always a crisp 60 degrees. If you’ve ever driven along I-44, you’ve seen the billboards. A lot of them. And a few painted barn roofs, too. Many of them identify Meramec Caverns as the one-time hideout for Missouri’s most infamous train and bank robber Jesse James and his gang. Sounds to me like a great place to get away and hide out from the heat for a while.

The story, as shared in complete earnest by our highly knowledgeable and enthusiastic tour guide goes something like this: Because the cave was a good source of saltpeter (or potassium nitrate), which was necessary for producing gunpowder, The Union Army used the cave as a munitions factory during the American Civil War until a group of Confederate guerrillas blew it up and put it out of business. Among those guerillas were the James brothers, Jesse and Frank.

Then in the mid to late 1860s, when the brothers began their crime spree, they remembered the cave and returned to use it as their hideout. It was a good one, too, because on at least one occasion a pursuing sheriff figured out their hiding spot, stood guard at the entrance, and waited to starve the criminals out. The man waited for three days before creeping further into the cave to discover a second exit through chilly 40 degree water that feeds into the Meramec River.

It’s just the right kind of story to capture the attention a couple of squirrely boys who have been forced into an afternoon of cave adventure fun. The story continues to capture the imaginations of around 150,000 cave visitors per year, and countless others who drive along I-44, wondering whether they should stop.

So I suppose it’s probably not a huge surprise that it isn’t likely true. I mean, yes, the cave, which explorers originally named Saltpeter Cave, did serve as a mine and munitions factory for the Union Army, and it was attacked by Confederate Guerillas. There’s even a chance Jesse and Frank James were among the soldiers responsible. But there’s really no reliable evidence that the brothers ever returned to the cave. In fact, it seems unlikely that they did.

The “proof” of the story comes from Lester Benton Dill, the man responsible for developing the renamed Meramec Caverns into a tourist destination. Soon after purchasing the cave, Dill began to expand its accessible parts, which led in 1941 to the discovery of a room beyond a crevice normally underwater, but slightly exposed during times of extreme drought. Dill claimed that the room beyond the crevice contained a strong box connected to a well known train robbery committed by Jesse James and his gang. He opened up the cave to create more access and the room now contains mannequins of Frank and Jesse and is a part of the tour.

But no one is totally clear on when Dill, a master marketer who was known to occasionally push the limits of truthfulness, made this fascinating discovery and the only witness who could testify to the truth of the cave hideout theory was a man by the name J. Frank Dalton, who at the age of 102 claimed to be Jesse James. An imposter, he said, had been shot and killed 67 years earlier. He also said that yes, of course the James brothers had used Meramec Caverns as a hideout and handy escape route.

Of course the James family and DNA evidence both denied the new Jesse’s identity claims, but he’d already breathed life into the tale Dill had been trying to spin on billboards all across Missouri.

So basically, this guy just commandeered the tale of an interesting historical figure, and wove it together with his own story, sort of making up history a little in order to promote himself. Frankly I don’t know what kind of person might do such a thing. But personally I don’t really mind so much, because Meramec Caverns does make a great hideout on a hot day with bored kids, and a little tall tale doesn’t change that.

The cave features all kinds of wonders, including an amazing formation that looks like a genuine stage curtain on which the tour guides project lights and patriotic images while a recorded Celine Dion belts out a rendition of “America the Beautiful.” It’s easily the weirdest thing I’ve ever experienced on a cave tour, and that’s including the James mannequins.

But it’s a literally cool tour in a figuratively cool place, well worth the stop if you find yourself driving down I-44, or in the middle of a heat wave with bored, cranky brothers who need to have some mandatory fun.