I did a lot of research with Ken Elvsaas on this.
I have a document and story i will share with you all this evening

I made a ton of phone calls about this several years ago.  The Sherrifs Dept is actually who gets called when a homeowner complains. They said, it is ok to have it on the boat you are using as long as it is raised from the water with a plastic bag covering the lower unit. However, the Game and Fish Dept said, the sin reads "NO INTERNAL COMBUSTION ENGINES ALLOWED" which means it can not be on the boat.  Kind of a GREY area in our world so full of Rules, Laws and Regs.... ????????

Hey Troy.  Didn't know you lived in Fall City.  So do I.  I have a lil 12' fiberglass boat (pretty easy for one guy to drag around).  We bought it for duck hunting. You are more than welcome to use it whenever you want. I just trip over it in the garage until the birds can die anyway. Also, I have the fiberglass repair stuff in the garage and, if you still have your lil Livingston, I'd be happy to help you patch it up.  Give me a call.  Don  206.551.6679

Well not so unlikely a few years back on shady or was it shadow lake I never keep those two straight. A boat with a gas motor was sunk right at the launch huge oil slick what a mess.The State told me that the reasons was if your electric motor went out then you might want to use your gas motor to get back to the launch. Also they said even if you trim motor out of the water it could still drip. I don't think a few drips would do near the harm that a home owner does with lawn fertilizer.
Last year Spring Lake a home owners heating oil tank leaked you should have seen & smelled that mess. I called & they said were aware of it. The lady was like its not that big of a deal cause diesel will evaporate fast.  
All I can say both of those lakes are crap now after the spills & they use to produce good fish.

I think it has to do with if the boat went down, the gas tank n oil n stuff like that would get into the lake. On a small lake that could be devastating. Although highly unlikely. I can see why they have the rule. Don't get me wrong tho I'd love to fish small lakes outta my Nitro anyday rather than my little boat if I could.

Another reason this state sucks! I mean serious? You aren't even running it!! Maybe the sight of the motor scares the fish...........

Oh man that sucks about your Livingston. You gotta get a little boat. You have no choice.

Ok so with soaring gas prices you would think a guy could use one of the many WDFW boat launches on the numerous small lakes around our fine state to launch a boat and fish with just the trolling motor.   Well NO you cant.  Nearly every lake within 20 miles of my house ( fall city) with the exception of sammamish is no motors allowed!   When did this all happen.  Good thing I bought this boat I cant use!  Ok I'm done I feel better now. 

My livingston got speared by a tree this last winter so now I guess I'm screwed