I am on salary with a Agency. I live in one town, but I am based our of another 35 miles away. Often times, I am asked to take supplies back and forth including payroll. Am I due milage for this?

It should be in their policy procedures if you are to get paid mileage.
I sure would bring it up to them with the price of gas

Hi, ppoo!

Greetings and WELCOME to the site! I just moved your question that you had posted in Introductions to this topic area so that it would get the most exposure to those who are best able to answer it. Introductions is for people to introduce themselves and we try to not ask questions there.

I do note that you have already received one, fine answer in the post above this one.

We would appreciate it if you would return to Introductions sometime to tell us a little about yourself though, if you would be willing to do that.

Thanks!

Are you asked to take the supplies multiple times per day, or is it "take it home when you go, and bring it back in the morning when you come in"? If it's the latter, then no. It's your choice to live 35 miles from where you work, and you aren't due mileage for the commute. If they are asking you to move supplies during the work day, you may be able to be compensated for that, but it depends on what your employment agreement says, and company policy.