*The census mentions the following arrastras in this county: Conly & Company, 1; J. W. Anderson, 1; J. H. Johnson & Son, 1; Temple, Wood & Company, 1.

There are probably one hundred arrastras in the Territory, some of which are propelled by water and others by horse-power. As water is sometimes short, and Indians occasionally steal the horses, arrastras of either class are often idle. Some are abandoned for fear of Indian assaults. Arrastras are now running in Walker, Martinez, Bradshaw, Turkey Creek, Hassayampa and some other districts.

In Mojave County there is one stamp-mill, that of the Morse Association, at Hardyville. It has ten stamps, driven by steam, and the necessary pans and settlers. It was erected to work the gold ores from the celebrated Moss ledge, but is now idle.

*The Big Bug mill has one arrastra and the Thunderbolt four.

*The list of mills in Clear Creek, Boulder, Park, and Lane Counties, Colorado, is imperfect, account having been taken of such only as were running in the summer of 1870; and even of these, I fear, (full returns not yet having arrived,) a number have been omitted. The census returns, bowever, do not even contain as many as are here given. Several costly mills (idle) are at Empire.