We were base camped over on the North Yuba River and drove over to this area for a day of exploring, well we found that there's a lot more to see here than it's possible to see in one day.
When exploring in the forest, it's not like the desert, roads shown on the topos have become overgrown and don't exist anymore. Cabins, cemeteries, and mines are hidden or lost in the forest, you can be right on top of some cool site or ruins and not even see them. I was unable to find two cemeteries shown on the topo, I had to give up due the loss of daylight.

  This is one area that I would like to come back to and do some more detailed exploring some day. We hit many town sites, but most did not seem to have anything left except for the hydraulic mines and miles of overgrown ditches that were used to deliver water to the mines. 
  The sites we visited include;

Port Wine:
  Shown on the map in 1853, placer mining petered out in 1851 and was replaced with hydraulic mining which brought life back into the town. Stories about the naming of the town include miners in the 1850's finding a barrel of Port hidden in the bushes and another story tells of finding a keg of cognac. Port Wine had a Wells Fargo station and a post office between 1861 and 1865. According to the Alta in 1854; between $30.00 to $100.00 was quite common per man per day. In 1863 a newspaper reported that it was a sober and religious town with a strong Welsh presence. Many hydraulic mines were also reported in the area. 
  In 1853 the Downieville Mountain Messenger reported "...The town looks remarkably handsome. The stores, saloons and shops bear a neat and clean apperance, which denotes characteristics of comfort and cheerfullness among the population. The wide street, with its tall liberty pole in the centre, looks fine....Owing to the short water season, the mines have not paid as well as anticipated". 

Queen City:
  Shown on the map as a considerable mining community in 1867 and the Golden Gate Tunnel is mentioned in Mining Press in 1861. I can't find much else on this site, I did find overgrown water ditches here.

Grass Flat:
  Shown on the map in 1867, with considerable hydraulic mining done here in the 1870s. Site of the Pioneer Hydraulic Mine with it's 1500 foot drainage tunnel can be found here also.

St. Louis:
  Shown on the map in 1857, and was known to have been a rich mining camp. In 1853 San Francisco newspapers reported that the diggings were rich and the camp had over 150 houses and a post office was established in 1855. In 1859 a 6000 foot tunnel was blasted into the hillside and the majority of mining was done here by hydraulic mining. In 1868 there were up to 12 hydraulic mining companies at work here.

Pine Grove:
  Shown on the map in 1853. The town was said to have 500-600 inhabitants in 1858. The Mining Press in 1861 reported that $6000.00 worth of gold was washed out from one tunnel in 8 hours and in 1879 it was reported that there was still some hydraulic mining going on here.

Howland Flat:
  The town dates back to the 1850's and had several stores, saloons, a theater, a brewery, a bakery, and a Wells Fargo station. In 1867 the Alta reported the population to be around 1200 people and the total output from the mines at that time was $3.5 million dollars! In 1854 a shaft was sunk at the base of Table Mountain, where it struck a rich branch of the famous Blue Lead. The town took off when the great Yuba River Canal was completed around 1856.
  In 1863 the Downieville Mountain Messenger reported "... No care has been taken to keep the streets clean, and improve the looks and convenience of the houses. Waterworks to secure the town against fire... the scourge of our mining towns...have as in most other places, been neglected."
  The population dwindled around the turn of the century but Howland Flat was still a small community until World War II.