Where does TurboTax let me enter charitable miles driven?

[BMcCalpin]

Go to Federal->Deductions & Credits->Donations to Charity in 2017 and click on Start or Revisit.

The next screen should ask for the name of a charity that you donated something (even mileage) to.

The next screen should be "Let's enter your donations one at a time". Look down the list - you should see that "Mileage and travel expenses" is the fourth bullet. Click that and you will be able to enter charity mileage.