This is a big-leaf maple down the creek a ways (maybe a mile or so?) below North Falls. Hardwoods like this don't add girth, generally speaking, as quickly as similar-aged conifers, so I'd guess this tree is in the neighborhood of a century old or so. When it was a mere sapling, it sent roots out in many directions to find water and the nutrients it needs. One of those became well established near what I'd presume was the then current soil level. In the past 100 years or so, soil has been removed by some combination of erosion, creep, and perhaps other minor mass transport mechanisms- more substantial earth movement would have tipped the tree more, or knocked it over completely. We rarely see major changes to the earth's surface outside of catastrophes and disasters, but here's a subtle hint at how it changes in tiny annual increments. Over a century, those slight changes add up.