What is that?

Today I woke up and decided it was a good day to rome around the woods surrounding my house. We live on 10 acres of land in about 1000 acres of logging country. There is a little creek at the edge of our land, that I have not visited in at least 3 years. I made my way out the door and was instantly greeted by the pouring rain. But being that I have lived in Oregon for 18 years, I am numb to the rain(lol). I just put on my mud boots and treaded on. I had to turn back to the house for pruners when I discovered the trail was almost non existent due to over grown blackberries.
As I went on I walked to parts that I never have before. It was fun. There are few things more therapeutic then spending time in the quiet of nature.


As I made my way down to the creek I noticed a tree with a large white streak on it. I thought it was a cool formation of tree sap. I got up to it and poked it, discovering it was a slimy gooey something with two slugs in it.

That is what inspired the title of this entry. I can't figure out, what is that?
Being that my mind tends to go to the gutter, I got back to my house and searched the internet for "slug mating." It looks like it, but their "product" is the size of a dime. The stuff I found was about as big as my boot.

So do you have an idea what it is? Please add a comment to help me solve my mystery