Pinnacle Mountain State Park has gone through several changes over the past century. In the 1920s, the area’s rocky slopes became the perfect place to harvest shale and sandstone for a variety of construction projects. The eastern slope of Pinnacle Mountain, where the East Summit Trail is today, was the major source of sandstone used to build the Lake Maumelle Dam in 1956. Segments of the East Summit Trail and the Base Trail follow the old quarry roads.
In total, six quarry sites were established on the land. These sites can still be seen today, if you look closely. Pine thickets, eroded road beds, and bulldozed rock features throughout the park are remnants of the old quarries. The park’s Visitor Center and parking lots were built within one of the major quarry sites in order to avoid further environmental damage to the park.
One of the most aesthetic remnants from the park’s quarry days is the Quarry Pond, located across the parking lot from the Visitor Center. The pond was formed after quarry operations left a depression in the ground, which collected rainwater and highly acidic groundwater over the years. Due to the high acidity, no fish or other life forms, except blue green algae, live in the green water pond.
Park visitors can pedal boat around the pond during the day, and are able to see straight to the bottom through crystal clear water. However, as daylight turns to dusk a chorus of frogs can be heard surrounding the pond, a sound signaling a return to life in the acidic waters of the Quarry Pond; another change taking place at Pinnacle Mountain State Park.