Underground Service Alert provides a free and effective Damage Prevention Service that protects the communities and underground facilities in Central / Northern California, and Nevada. Underground Service Alert (USA) began operation in May of 1975 & incorporated as a 501 (c)(6) Non Profit Mutual Benefit Corporation in 1986. Our objective is to receive planned excavation reports from public or private excavators and to transmit those planned excavation reports to all participating utility members of Underground Service Alert who may have facilities in and around that excavation site. Our members will either: 1) mark or stake the horizontal path of their facility, 2) provide information about the location of their facility, or 3) advise the excavator of clearance, for facilities that they own. List of Holidays The following is a list of Holidays recognized by California and Nevada. Both California and Nevada One-Call Laws do not allow Federal or State Holidays to be included as part of the legal notice for the excavation notification. Counties California (Central and Northern Counties) Alameda, Alpine, Amador, Butte, Calaveras, Colusa, Contra Costa, Del Norte, El Dorado, Fresno, Glenn, Humboldt, Kern, Kings, Lake, Lassen, Madera, Marin, Mariposa, Mendocino, Merced, Modoc, Mono, Monterey Napa, Nevada, Placer, Plumas, Sacramento, San Benito, San Francisco, San Joaquin, San Luis Obispo, San Mateo, Santa Clara, Santa Cruz, Shasta, Sierra, Siskiyou, Solano, Sonoma, Stanislaus, Sutter, Tehama Trinity, Tulare, Tuolumne, Yolo, Yuba Nevada (Entire State) Carson, Churchill, Clark, Douglas, Elko, Esmeralda, Eureka, Humboldt, Lander, Lincoln, Lyon, Mineral, Nye Pershing, Storey, Washoe, White Pine