Small air fields

[Phax]

I live near many small airfields and I am wondering if I have to contact all of them there are 3 that I am with in the 5 mile range.. how ever there is no contact info for them anywhere I look.

This is a screen shot from Airmap.io and my house is at the black dot.
I was flying at a local park and a small manned aircraft was flying extremely low around 200 ft. he was not landing either, I had to descend my P3A as fast as I could, I was actually higher than he was.... and keep in mind this is by a park but also a residential area.

 

[J&L]

I have a crop duster grass airstrip just down the road and on the be4ufly app it says I'm in the 5 mile bubble. And I need to contact them. They fly 3-5 times a year so I just don't fly when I see the hangar open.

 

[Mark The Droner]

Since they have no contact info, I would write a letter. They have an address, right? I'd write a letter advising them that you fly occasionally at such and such a location at your max height. I'd include my phone number.

That's MHO. Nine other people might have different opinions.