Chirping sound 55-75 MPH

hey all, I am currently traveling across the country and yesterday I started to notice a "chirping" sound when traveling between 55 and 75 ish mph. The chirp doesn't seem to be related to any type of suspension nor throttle related it's not constant but comes and goes. The truck, 2012 TRD seems to be running just fine other wise. I apologize if this is a repeat question however I didn't have much time to search the forums as my service is next to nothing up here in crater lake.

I'm not overly concerned with the noise but I do have another 3-4 thousand miles left in my planned route before I get to me destination. I will say it's annoying as all hell without having tunes on.

Any suggestions or thoughts are much appreciate.

I had the truck checked by a Toyota tech before we left and there were no concerns on their part - this was roughly 1000 miles ago, the chirping started yesterday.

 

Mirrors in the wind?

 

I don't think so, haven't heard this sound before - sounds more like rubber on metal - but again it's a bit bizarre as it doesn't happen with bumps in the road or anything like that. Also at those speeds it doesn't sound as if it's pulley or belt related as the noise doesn't correlate to the Rpms.

 

Anyone have any additional insight? In southern Montana now with another 3k miles or so before I do the 90k service back in Boston and would love to be able to troubleshoot this beforehand!

Thanks all,