Is Mileage stored in speedo, or in computer?

Does anyone know if the vehicle mileage is stored in the speedometer or in the computer? I will have to replace my speedo cluster and was wondering if I should get one with similar mileage, or will my original mileage reappear when I hook it up. I own a 2001 windstar sel with 40,000 miles. Thanks for the info
Dave

Both.

Both.
Thanks for the response. Which will display on my new spedometer, the mileage in the new cluster, or the original mileage stored in my computer?

Thanks agian

The mileage stored in the speedo head will be the one displayed.

Should anyone check the EEC, they *might* notice a discrepancy, and they certainly *could* find it.

Just take a dated photo of both the old and new speedos with the current mileage displayed, and place it with the title with an explanation.