The low rumbles of the fog signal and flashing beam of light from the powerful lens have guided mariners away from the perilous waters surrounding Point Arena Lighthouse since 1870. After the great earthquake in 1906 and the rebuilding of the tower in 1908, Point Arena's navigational aids continued to warn ships away from the peninsula off Northern California's Pacific coastline. The original tower was replaced with a concrete cylindrical tower that rises 115 feet from the headland. This became the first lighthouse tower in the United States constructed with materials found to be superior to the stone and masonry lighthouse structures of the past. The new tower, crowned with a nearly 13,000-pound first-order Fresnel lens, sent a beam of light 20 miles out to sea and continued alerting ships of the dangers just offshore.