© mandj98 / flickr 
Nature can take hold in precarious places. Chapel Rock on Lake Superior has a single tree perched atop its column. By rights the tree should not be there: the small surface area of land on the top of the rock is insufficient to sustain a tree of this size.
There is hardly any topsoil, certainly not enough for an obviously thriving tree. How then does it flourish?
Image Credit Flickr User DJblock99
Image Credit Flickr User Jim's Travels
Look a little closer and you will see the answer – that rope on the right of the picture is not, in fact a rope. It is a system of roots, extending and stretching over the edge of the rock to the main bluff where there are nutrients and water aplenty.
© mtsn / flickr Image Credit Flickr User mtsn
Yet how on earth did the root extend over to the mainland? Did it slither in some triffid like way until it reached the other side? Is there a Little Shop of Horrors thing happening here? If you can remember the puzzle about the hanged man in an empty room then you are moving in the right direction to solve one of nature’s mysteries.
© zoes_pictures / flickr Image Credit Flickr User eoz15
The answer lies in the type of rock upon which the tree is balanced. It is part of the Pictured Rocks National Lakeshore on Lake Superior, which lies between the city of Munising and the township of Grand Marais. Part of this National Lakeshore (the first so designated in the US, back in 1966) which ranges for 42 miles is 15 miles of colorful sandstone cliffs. Sandstone erodes.
© mtsn / flickr Image Credit Flickr User mtsn
Over the millennia the cliffs have been sculpted in to any number of wonderful shapes, from caves and arches to formations that look like human faces or the turrets of romanticized medieval castles. Chapel Rock is one such rock along the cliff side. Yet until one day in the 1940s the rock was not a pillar – it was an arch.
© davehogg / flickr Image Credit Flick User Dave Hogg
So, there is your answer. If, in your book, some people are born lucky then so, it seems, is the occasional tree. This one had established itself while Chapel Rock was attached to the main bluff of the cliff face. As it was at the edge of the cliff-side, its roots naturally grew towards the nearest source of fresh water and developed in to a long and strong system. Then, the fateful day came seventy odd years ago. When the sandstone had eroded to a point at which it could no longer bear its own weight, the whole archway tumbled to the ground leaving a pillar behind.
© mtsn / flickr Image Credit Flickr User mtsn
Yet instead of plummeting to the ground with the rock and the topsoil the roots somehow managed to cling on to either side of where the arch had previously been. The roots have continued to grow over the decades and are now thick and wooden (even though they would already have to have been very strong). They look, to all intents and purposes, as if they have deliberately struggled and strained over the chasm. As tempting as it may look, I can't find any record of any foolhardy sould trying to use the roots to clamber over to the column and tree.
If had been just a little closer to the arch then there is no doubt that the tree would have fallen. Instead it has puzzled many a visitor to this beautiful part of Picture Rocks National Lakeshore. You might say it’s an arboreal case of the chicken and the egg. Yet just like the hanged man puzzle, if you know how to look for the metaphorical block of ice the answer finally seems obvious.
