The sticker was hidden in a hole at the base of a sign post near the bottom of the trail leading up to Multnomah falls.
Clue 1
The word MULTNOMAH can be found by figuring out which letters should go along the line that seperates the white and black sides. The file name contained the hint 1of4 which hinted at Multnomah county, and the word spelled out down the picture was a hint at the falls.
Clue 2
Iversen in the clue refers to Simon Iversen who later changed his name to Simon Benson. He had the bridge at Multnomah falls built and it is named after him. If you follow the insructions that "Simon says" starting from the lodge it will take you to the bench right next to the sign post where the sticker has hidden.
Clue 3
The text hints that the sticker is defferent than it has been in the past. The picture is flipped horizontally and you are looking toward the bottom of the trail where the sticker was hidden. The file name hint WearingRainGear is because the sticker was attacked to a card inside a plastic bag.
Clue 4
This is a collage of photos from the area. There is some morse code hidden right below the H in Have that reads "in plastic" referring to the bag. The file name hint ZoomIn tells you to zoom in on the picture so you will see the morse code.
Clue 5
There is a lot in this clue. First off, being national leftovers day, you usually take your leftovers home in a doggy bag. The sign the sticker was hidden beneath had a sign for doggy bags.
There is quite a bit of hidden text in the clue that you can see by highlighting the text with your mouse. Hidden withing the text is "ROT13" wich will help you make sense of the others. There is a ROT13 converter here http://www.rot13.com/index.php. There is also more hidden text that turns Sam into Samuel Morse - Morse Code.
Beneath the text of the clue converted into ROT13 is the text "Multnomah Falls"
Above the text in morse coded, ROT13 is the text "near the ground"