Breaking Down the Mountain

Throughout the last few hundred million years Mt. Katahdin has undergone multiple natural events that have caused varying levels of degradation to the landscape. Glaciers dominated the landscape off and on throughout the Pleistocene Epoch (1.5million-10,000 years ago). This left hundreds of small basin ponds, rivers, streams, all over the area. The weight of the ice also forced rock debris to be strewn far from the place of origin. Some of which were boulders the size of houses, others minuscule pieces of granite known as grus. 

With all the glaciers having fully receded after the last continental ice sheet passed through around 25,000 years ago, Mt. Katahdin has had much of its weathering and erosion take place at the hands of the precipitation,epilithic organisms such as lichen or mosses, and the all mighty gravity. Whether from rushing springs streams from the winters melted snow, or the freeze-thaw that takes place much of the year due to Maine's climate, the end state is the same. Rocks, water, debris, trees, and such will move towards the pull of earths gravity. In the picture below we can see a culmination of many of these factors. Melting snow has created a steady streaming waterfall, the rocks are being broken down from lichens and mosses feeding off of them, freeze-thaw has riddled the granite with cracks and breaks, roots from nearby trees exploit these openings. With time passing, the roots of all the plants eat away at the rocks enough for the water to wash them away and smooth into alluvium which will line the stream beds and river banks. 

A waterfall stream showing water erosion from gravity's downward pull, rock decay, chemical decay from the lichens, and even root pressure from the nearby trees.

Here you can see snow still on the top of the mountain in early June. Snowfall varies from year to year, with melt times also varying due to climate fluctuations. Once melted, this water will carry pieces of colluvium down the mountain. 

http://www.5lakeslodge.com/katahdin-hiking-hunttrail.asp

http://maineanencyclopedia.com/geology/