Thanks for reaching out!
While it is technically a boot, we do carry the Lowa Renegade GTX Mid Hiking boots in a narrow width (in the 'Sepia' and 'Deep Black' colors). If you are specifically looking for a shoe, Lowa does make the Renegade GTX Lo hiking shoe in a narrow width. While we do not carry that model at REI, we do offer a special order option that would allow you to order that shoe directly from Lowa. That process can only be done in your local REI store and is dependent on the vendor for availability, shipping, and processing times.
Hopefully this helps, thanks!
@GET do you know the width of your feet (A, B, C, D)? In general, men's footwear is based on a D width and women's footwear is based on a B width...so, if you measure somewhere between an A-C width and shorter than a US 10.5 length (men's sizing), you could consider some women's shoes/boots in your search as well, as they will typically run more narrow than a men's shoe/boot.
You might also look at shoes/boots from Oboz and Vasque, which are two brands that tend to run narrow but aren't necessarily offered in narrow versions (like @REI-JohnJ's suggestions).
Hope this helps!