I'm in the Minneapolis/St. Paul area and around 9:30 on August 4th 2017 I saw a bright light that got dimmer moving from the tree line to the east up and to my left fairly slowly, and steadily getting dimmer. There were no flashing lights like an airplane. Around 5-10 minutes later I saw another light exactly like the first in nearly the same place going the same direction, they both faded and disappeared. I grew up in the north and have spent many nights out in hay fields staring at the sky but sadly I have never really studied astronomy and my guess at brightness is based on Google images. My first guess would have been a satellite but seeing two on the same path makes me think otherwise. Thoughts?
According to CalSky (https://www.calsky.com), there were two Iridium flares visible low in the south-east from Minneapolis at 21:18 (Iridium 60) and 22:28 (Iridium 55) on that evening. Both would have been about 15 degrees elevation and both in the right ballpark for brightness.
Iridium flares occur when the rising / setting Sun's rays bounce off the antennae or solar panels of one or other of the Iridium communications satellites. By their very nature they occur around dusk or dawn. They'll flare up, persist for a few seconds and fade away.