sólo que al otro lado del “Río Uruguay”.

The “que” in this phrase really seems to throw me off. Should it be there? What purpose does it serve?

¡Hola Steven-W15!

Thanks for your question! This is indeed a little tricky.

Using sólo que in this sentence makes the contrast sound a little more emphatic than just using sólo would, and sólo que also sounds much more natural. Essentially, we can think of it like this: it's as though there is an invisible está present after sólo que (so, if we take a more simplified version of this sentence, it's as though we're saying La carretera está casi paralela a la ruta, sólo que está al otro lado del Río Uruguay). And just as you should use sino que “but rather” instead of sino when it's followed by a phrase with a verb, it's better to use sólo que instead of just sólo here, due to that invisible está.

I hope that this explanation is helpful! Let me know if you still have any questions!

Saludos,

Liss
 

Hola Liss, 

The explanation was very interesting and informative! 

Saludos,

Ricardo

Indeed, thanks Liss. I came across a similar example in a song just the other day as well (i.e., where the verb was implicit/invisible).

Nice to see you still active here in the forum, Ricardo!