This conceptual model illustrates how water and sediment transfers can affect erosion in distant regions. Three distinctive erosion regimes exist along the channel:  glacial valley carving, canyon cutting, and lowering of the High Plains.  These result from the action of glaciers, periglacial and other hillslope sediment transport, and fluvial incision in the streams.  Cooler climate at high elevation supports glaciers and periglacial hillslope processes during glacial periods that deliver sediment to the streams (small arrows).  Fluvial downcutting occurs during deep interglacials when the sediment supply from upstream declines.  Juxtaposition of hard crystalline rock in the Front Range against soft sedimentary rocks of the High Plains result in the most rapid downcutting on the High Plains, leaving a series of alluvial strath terraces.  A knickpoint propagates upstream (large arrow) into the hard crystalline rock, carving canyons in the Front Range.  (from Anderson et al., 2012, Figure 4)