Because the designated gathering area is on 5th avenue at the railroad tracks. There is a sign on 3rd ave at Humboldt stating this.

This is also a problem along much of El Dorado, including in front of my house. I find trash in my yard and bushes nearly every day - cigarette butts, food wrappers, bottles, broken glass, phone cards, etc. I've also found people lying on my lawn and walking through the yard to take lemons from my trees. My neighbors also found human excrement (!!!) in their back yard. This would not be a problem if those who gathered were respectful of our private property and did not . But, as things currently are, this is a huge source of frustration, not to mention hours of time spent cleaning, and worrying if we continue to ask people to leave there will be retribution one day.