Woolsey Flat or Woolsey's Flat was a historic mining town located on the San Juan Ridge, located about 17 miles northeast of Nevada City and about 3 miles northeast of North Bloomfield.

[4] It lies on a part of the auriferous (gold bearing) channel which runs the length of the San Juan Ridge.

[9] In the 1856 presidential election, a total of 214 votes were cast, of which 112 were for Buchanan, 104 for Fillmore and 4 for Fremont.

[10] By the 1860 election, the number of presidential votes had fallen to 108, of which Lincoln received 27 and Douglas 41.

[15] Nevertheless, by 1857, Woolsey advertised that "having determined to remove to the Atlantic States," his mining claims were for sale.

One newspaper reported that at Woolsey's Flat "there is not sufficient water to supply one fourth of the demand" leaving the town "nearly depopulated.

[19] As one paper reported, at Woolsey's Flat "the banks are so high and steep, that there is constant danger of their caving in and burying the workmen.

[24] In 1874, it was reported that "[t]he country about Woolsey's Flat has been settling and sliding very fast the last three or four days and the inhabitants of that berg [sic] are tearing down and moving houses at a lively rate.