The Dover district, Morris County, N. J., one of the oldest mining regions in the United States, has been active intermittently since the early part of the 18th century, and has yielded in excess of 26 million long tons of iron ore valued at more than $100,000,000. This is about 70 percent of the total production of iron ore from the State of New Jersey. Since 1940 about 500,000 tons of magnetite lump ore and fine concentrate have been shipped annually from the Scrub Oaks, Richard, and Mount Hope mines—the 3 producing mines in the district.