How can you tell how old a Grape Vine is?

Question

We have a grape outside our house in the woods that is over 300ft long and wish to find out the age, if possible.

Answer 1

I searched through the web for awhile, couldn't find any information on fixing age on grape vines aside from DNA testing. However, grapevines commonly live for 100 years, and the oldest one in the world has been certified at 400 years. You might try talking to the county extension service - they might have more information for you. This link will help you find the nearest office:
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm