ちょう距離 きょり自然 しぜん歩道 ほどうであれば
chōkyorishizenhodōdeareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 長距離自然歩道

1. If it were a long-distance nature trail; If it is a long-distance nature trail

Ba Conditional