Banks Lake state park, located in northwestern Washington, has a very unique climate in which its geographical features undergo large amounts physical weathering. Due the extreme heat and cold that Banks Lake experiences in its virtually 2-sided climate, Summer and Winter, most of the large rock forms on display there are littered with fissures and joints. These sizable cracks in the rock face allow for great Rock Climbing and help boost tourism in the off-season.
With the high levels of rain fall that this Whashington state park experances 9 out of the 12 months, it is not uncommon to see many cracks in large rocks, especially waterfront rocks, due to a mechanical weathering process called Frost weathering. When water from the lake or from rain seeps into small exicting cracks, caused by pressure release, and freezes it brakes the rock. Because of the potential of rocks freezing and braking of into the water, once the lake unfreezes each year the park rangers have to drive out and mark off parts of rocks that have fallen into the water so that boaters don’t hit them while driving.
