Mystery 10.9 bolt

[stan_5150]

2006 Envoy SLT (178K).

I found a loose 10.9 bolt laying on the lines between the cooling fan and the engine block. I accomplished a visual check near the front of the engine compartment but I can't see anything apparent. I've looked online and I've looked at the water pump area but everything there seems in order.

I was driving last night and noticed a noise when making right hand turns. I checked for debris but didn't find anything, and upon inspection of the engine compartment I ran across this bolt.

If anyone has any ideas where I should look it would be greatly appreciated. Thanks.