The inscriptions and petroglyphs at El Morro are an important link to the past, but they are gradually deteriorating as sand grains wash away, rocks crumble and fall, and lichens and clay deposits cover the historic carvings. Part of this heritage is fading, and the National Park Service works to delay that deterioration for as long as possible by monitoring and treating threatened inscriptions and the rocks in which they are carved. When the loss of an inscription is imminent, conservators may use grout to fill holes and keep out water, strengthen loose rock around eroding inscriptions with consolidants, and secure rock slabs with drilled-in pins.