You will need to be familiar with the concept of the hidden fastness of the Rangers. Please read these:
Look
HERE.
“Tolkien actually made a note, now filed among his papers at Marquette University, which stated that Aragorn's people lived in the Angle, between the Bruinen and Mitheithel rivers. The Mitheithel river, as it turns out, does lie about 100 leagues (or 300 miles) east of the Shire.” (From the Article above)
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Hidden Fastness
The Rangers 'hidden fastness' and #'s – Barrow Downs – by Lindil – Post 13
“I recently came across a quote of David Salo who says that a scrap of writing at Marquette [where all of JRRT's manuscripts [or a lot re: LotR anyway] are kept , and it said that the rangers 'hidden fastness' was in the Angle of the Mitheithel and the Loudwater.” (From the Article above)