Tecumseh Sparrow Spivet lives at the Coppertop Ranch (just north of Divide, Montana)
This cache is not on the given coordinates, but not very far also, but the coordinates you have to find and put in geochecker are very very very far away, then you will receive the right ones, I swear you!
On the first page, it was clear this should make a nice cache!
Discussing with Forrestc, It appears this was may be not in the middle of nowhere. The room of the 12 years old boy in the Coppertop Ranch could really have been there!
Find out the coordinates of T.S. Spivet room and you receive the coordinates!