For some time now I've kept an eye out to the west, hoping the afternoon clouds would hang on. Usually the summer sun burns them off, but, in this case, they lingered past sunset, so I lit out for Calico Rock, about 20 minutes away. Another such journey got me stopped by a cop (ok, guilty, I was speeding), and missing the sunset. This time I timed it perfectly, and got my best shot with the first three images I took (top panorama). Staying past sunset got me several more interesting shots of clouds and the River.
For students, to capture the sun rays as in the first image, wait until the sun is right on the horizion. Use a very high f-stop (f22 in this case) and meter accordingly. Like all sunset photos, the high contrast situation will require some adjustment, so shooting in RAW is necessary.