Grand Caverns was discovered in 1804 by Bernard (Barnette) Weyer while trying to retrieve one of his traps. Weyers Cave opened for tours in 1806, making it the oldest continually operating show cave in the U.S. The caverns were also called the Grottoes of the Shenandoah until named Grand Caverns in 1926. Grand Caverns was declared a National Natural Landmark in 1973. In 1974 the caverns and surrounding acreage were gifted to the Upper Valley Regional Park Authority by its then-owner Gladys Kellow and became known as Grand Caverns Regional Park. On October 1, 2009, the Town of Grottoes took possession of its namesake caverns, and consequently, the UVRPA dissolved.