I must mention that your experience was quite incredible. Also, just a short note that this forum houses many many different people and their need to connect and express...some sane some questionable...but all in all we are a harmless bunch. Hope that you feel comfortable in sticking around.
It is incredible that there may have been a helicopter there too. Though I would wonder if this was one of theirs, as in alien. Just as a thought, not true logic. I hope that your meditations bring a greater clarity to your experience. You are both fortunate and lucky to have experienced this and also to not have come to any harm from your speeding in a rural road environment with quarries and all.
You will probably find many different explanations to your experiences here and some will even simply respond within your thread...I hope that some of it will be helpful.
...thanks for sharing.
peace - dreamrunes