The reports from the mines continue to be of the most favorable character. Gold has been discovered upon Trinity River, about two hundred miles north of Sacramento City, and the digging has proved to be equal to that of any of the other placers. The mouth of the river, which empties into Trinity Bay, has been surveyed, and, being considered a very good harbor, a town has been projected, to be situated upon the shore at the mouth of the river. Rich diggings have been opened near Mariposa, and on one occasion, a mass of gold and quartz, weighing fifty pounds, was taken from them, and sold for sixteen hundred dollars. Several important discoveries have been made on the Mokulumne River. Out of one hole, three men, in two days, took the sum of four thousand dollars. It is thought that more bullion will be obtained during the dry season of the present year, 1850, than has been received since the commencement of the gold-digging. This seems to falsify the predictions of some persons, that the gold region would be speedily exhausted. The following is an account of some bloody transactions upon the North Fork of the American River. We extract it from the Pacific News of May 15th, 1850:-- "About two weeks ago, a party of Indians came stealthily upon a few miners who were sleeping after their work was over in their tents on the North Fork, some twenty miles above Auburn. Before the Indians gave any warning to the whites of their presence, they killed two, wounded another, and then succeeded in making their escape. On Friday of last week, a trader, who was travelling with his team, was surrounded by Indians when about fifteen miles above Auburn. The arrows from their bows took effect upon his person, and he only saved his life by a precipitous flight. They carried off his coat which he left in his wagon, with $600 worth of gold dust in the pocket. They also robbed his wagon of several valuable articles. Upon receiving news of this attack at Auburn, a number of men set out on horseback, in pursuit of the Indians. They overtook them in a valley not far from Auburn, and found a large party of them drawn up to meet them. The Indians were armed with bows and arrows and had one gun. The whites attacked them, and soon put them to flight. The Indians left a considerable number of dead behind them, and it is supposed that they carried off many more. Two of the whites were wounded with the arrows of the Indians, but not fatally. "It is believed by many of the miners that there are white men among the Indians, inciting them to hostilities. It is pretty certain that a German doctor has been leading them on in their attacks. A meeting was held at Auburn, last Monday evening, to raise a company of volunteers for the purpose of scouring the country, and making war upon the Indians wherever found, so long as they maintain a hostile position, and a number of men were enrolled."