Hello Zbip57. You have solved the mystery for me! I was right at the spot where you see the interstate "12" marker above Rimini, right in between those small yellow circles, and on the southern edge of the gray wedge. Those small yellow circles are the "landing strips" on private ranches. I was flying north from my position. I see that if I had flown south, I would have been flying outside of the gray wedge, instead of into it by flying north. I may have to try flying south and see what happens? I'm confused why this did not show up on B4Ufly, and it said I was good to fly? Can you please confirm for me, is "Mapbox" a flight clearance app? If it is, it is much much more through! I am so very happy that you educated me on this!!!! So much to learn.
On a side note, if you notice the rather small lake located approx. ENE, right at the edge of the outer yellow perimeter? There is an RC airfield located there. Those guys fly rather large (8'+ wingspans) RC planes there all the time, but I really don't think they ever come close to 400' (it's in the valley so no need). I'm going to go out there and see if my altitude is restricted there as well.
On a side note, if you notice the rather small lake located approx. ENE, right at the edge of the outer yellow perimeter? There is an RC airfield located there. Those guys fly rather large (8'+ wingspans) RC planes there all the time, but I really don't think they ever come close to 400' (it's in the valley so no need). I'm going to go out there and see if my altitude is restricted there as well.