- Who's gonna make us, tenderfoot? You?
- I am.

5 seconds sound clip from the Back to the Future Part III movie soundboard.

You can hear this line at 00:55:01.849 in the DVD version of the movie.

Quote context

[...]

- Listen, can I try that again?

- Yeah, go ahead.

- Hey, just tell me one thing. Where did you learn to shoot like that?

- 7-Eleven.

- Buford, you sure that blacksmith is gonna be at this here shindig?

- Sure he's here. Everybody's here tonight.

- You gentlemen will have to check your firearms if you want to join in on the festivities.

- Who's gonna make us, tenderfoot? You?

- I am.

- Marshal Strickland. I didn't know you was back in town.

- If you can't read the sign, Tannen, I presume you can read this.

- Pretty tough hombre when you're pointing a scatter gun at a man's back.

- Just like you, Tannen, I take every advantage I can get.

[...]