Earlier this evening while talking with friends on the Chehalis Indian Reservation, when two of us happened to notice what appeared to be a bright star, yet in the same slice of sky a few other stars were becoming visible and there was a commercial airline following a north bound flight plan, and it was then (less than 20 seconds we could see the "UFO" unidentified object had already descended to a bit over the I-5 flight corridor, and was still descending so fast we thought maybe it was a jet crashing.
At its height (far above commercial lights and lanes) this "UFO" appeared twinkly white just like stars, it took approx. 35 seconds to descended to under the airline lights, then another 10 to pass by the tops of 100-140 foot Cedar and Douglas Fir trees. As the "UFO" passed, at a steep descent, the color changed to a greenish blue and got lighter in color from front to back, appearing to be 2 or 3 times the height of the trees.
The "UFO" was totally silent, crossed from approximately 50 degrees above the Southern horizon, to approximately 15-20 degrees about the Northern horizon and covered the heights and distances mentioned in about 80 seconds or less. There was no flash, explosion, nor other indication of ground impact.
The only thing that was more worrying than seeing an "UFO" object like that after over half a century with never seeing anything come from so high, to so low, so fast with no heat, smoke, flame, or exhaust, was on my way home, as I got closer to Interstate 5, I began to develop an odd headache accompanied by a sound I know from being a studio musician had two tones...one in the 22-42 hertz range and the other up in the 60 khz range (near a harmonic) and I got slightly nauseous with a dull headache. All physical symptoms faded away the further south and west I got from the Reservation.
There was one other person who saw it from start to finish, but since I heard of no other report yet, I thought I'd like to file one. mufon cms# 85490 UFO Sighting occurred on July.29,2017 over Oakville WA U.S.