Why is my gold connected?

[pokeii]

I finished the road on the farm last turn where the workers are still at and was noticed I'm now connected to my gold and corn. But how am I connected to the gold? I don't have sailing so I think I only need to look inside my border. I thought I needed to road the tile southwest from the worker to use the river to the left.

 

[civac]

The algorithm that calculates this has some issues. You can in certain situations jump from one river system to another if they touch adjacent tiles.

Edit: If you really want to kow badly: https://www.realmsbeyond.net/forums/showthread.php?tid=9938&pid=756320#pid756320

 

[ariosto]

If you have tile that is adjacent to both rivers that means that rivers are connected. In this case the tile 3S of capital is like this.

 

[pokeii]

If you have tile that is adjacent to both rivers that means that rivers are connected. In this case the tile 3S of capital is like this.

I noticed there in an earlier game but failed to see it here. Thanks!