We have a stream that runs through our Platte River Prairies that is strongly groundwater fed.  The relatively warm groundwater inputs help to keep the stream from completely freezing over.  On the day I took this photograph there was a margin of ice along the bank of the stream, but the majority of the stream was still open flowing water.

Ice patterns on the edges of a stream - The Nature Conservancy's Platte River Prairies

I was drawn to this particular patch of ice because of the layered patterns within it.  The more I stare at it, the more patterns and pictures emerge.