Towing Issues: Towed without any visible signage, apartment owners, aloha oregon

Question
I recently got towed from a private property (apartment lot in front of a friends unit I was visiting). I was parked there only 45 minutes before I went outside to leave only to notice my vehicle was missing.  On the parking lot where the only sign was located it was completely covered by foliage from a bush. I had to come up to it spread the branches apart & read it to determine who had my vehicle. I thought one had to have proper signage /notice that is appropriately visible to all drivers that they are in a potential tow way zone.
When contacted, the individual I spoke with was also the one who towed it, said there company (Beaverton Towing,Inc) only needs a contract with the apartment owners & it does not matter that I can not see the sign. This occurred between Beaverton & Aloha, Oregon. Please advise.

Answer
First of all the sign laws are State laws...

And the law is below..
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Oregon
98.810 Unauthorized parking of vehicle at proscribed property prohibited. No person, without the permission of:

(1) The owner of a parking facility, shall leave or park any vehicle on the parking facility if there is a sign displayed in plain view at the parking facility prohibiting public parking thereon or restricting parking thereon.

(2) The owner of proscribed property, shall leave or park any vehicle on the proscribed property whether or not there is a sign prohibiting or restricting parking on the proscribed property. [1953 c.575 s.1; 1979 c.100 s.3; 1981 c.861 s.24; 1983 c.436 s.3]


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Now the driver was partially correct in the fact that they need to have a contract and a signed authorization to do the tow...

But they do need signs per state law...

I am guessing that you were in that no mans land out in Washington County there, and the reason I say that is that Beaverton also has some laws regarding towing... (I am originally from Portland)