Just started the game and went to Beans first and a supply drop prompt happens and it's on the far side of the river and it can't be reached. Some pop-up about radiation but no other on screen indication of damage or anything, and next thing you know respawn with no way to get to the supply drop. Pretty pathetic start to the game.
The supply drops are just random. You don't miss anything if you miss one. I hardly went after them unless they were right near me. They are not needed and are not a big deal. Get all the treasures and you get tons of resources. I hardly ever used a vehicle in this game. You can find so many resources by walking and killing everything in sight. Just KILL, KILL, AND KILL!
Or just keep retaking outposts.