How old is this bag found on Harkers Island?

A snack bag found on Harkers Island last week has Cape Lookout National Seashore reminding people that plastic trash lasts a long time.

But just how old the Doritos bag is that was found is unclear.

The Cape Lookout National Seashore Facebook page posted a picture of the bag saying, "Wayback Wednesday -- This bag was found last week on the sound beach along the Soundside nature trail on Harkers Island along with other storm debris during a trail cleanup. The bag design looked "odd" to us, but we couldn't put our finger on why until we noticed the date in the lower corner -- 1979! While this was sort of a neat find due to its age, it serves as a reminder that plastic trash lasts a long time, in this case almost 40 years!

Some commenters to the post agreed, while others were unsure the bag is actually from 1979. Some said Frito-Lay is selling Doritos in retro bags. Others believe the bag simply would not have lasted this long.

WITN has reached out to Frito-Lay to see if they can help solve the mystery.

So far we have not heard back but when we do we'll let you know what they have to say.