This is the 10092nd most frequent Japanese word.
遠かろ
"遠かろ" is an archaic or poetic form meaning "probably far" or "would be far" in English.
遠かろう is used as a conjectural form indicating a perceived or assumed distance based on observation or knowledge.
ここからあの山は遠かろう。
That mountain is probably far from here.
遠かろうと is used to indicate a concession or irrelevance of distance in relation to time, suggesting it does not matter.
時間的に夜が遠かろうと仕事を終えなければならない。
Even if it is far from night in terms of time, we must finish the work.
遠かろう, here used with 思う (to think), expresses a subjective assumption or expectation regarding distance.