Long bright UFO caught over Detroit, Oregon

On August 20, 2017, a witness caught a picture of a huge string of light over Detroit, Oregon, USA. What is it?

Witness statement:

I was in the mountains above Detroit Lake, Oregon, taking pictures of the night sky from around 10:45 pm to 11:15 pm. After the fact, I found a light anomaly on two of my pictures, taken 10 - 15 seconds apart. Without a clear reference I cannot estimate the distance from me, but the anomaly appears to be at least hundreds of yards across. From the first picture to the second it moved to the West and slightly lower in elevation, and the far left section changed shape. The light color is yellow-white with brighter sections spaced regularly along it's length.