Perched dramatically atop a rocky outcrop at 2,000 feet elevation, the multi-tiered wooden observation tower at High Rock in Pen Mar, Pennsylvania rises against a warm summer sky in this hand-colored early postcard — a structure that drew thousands of Blue Ridge Mountain tourists each season to the beloved Pen Mar Park resort, operated by the Western Maryland Railway from 1877 until its closure in 1943. Small figures visible on the lower platform convey the tower's impressive scale, while the rustic stone base anchoring the timber-framed upper decks reflects the vernacular engineering of the era. Pen Mar was known as the "Playground of the Alleghenies," and High Rock was its signature scenic attraction; the tower itself no longer stands, making this card an important visual record of a vanished landmark. Published by the Pen Mar Souvenir Co., based on-site, with catalog number 218581 visible in the lower right.