Where do USGS topo tiles come from?

[navaid]

Hi,

I'm a long time user of TF and I love it!

I'm also a software writer and was thinking of integrating some USGS topo map tiles into an app I'm writing.  I can't track down where on the Internet you're downloading the indivdiual tiles from in realtime.  Where is this magical web service?

Thanks!

[Krein]

http://www.terraserver-usa.com

There is some documentation on the site about how to grab tiles, or you can figure it out from the URL lines.

Good luck!