The Dawn of the World, by C. Hart Merriam, , at sacred-texts.com
The Mokalumne say:
After a person dies and is buried the heart-spirit comes out and shakes itself to shake off the earth, and then sails away in the air and disappears--going northwest to the ocean. This may happen on the fourth night, or at any time between the first and fourth.
The Ghost goes to the ocean and enters the water and finds a large animal [probably a whale] whose breast it immediately lays hold of and sucks. If it does not take the breast of this animal it can not live in the ocean with the other Ghosts, but in from two to four days returns and reënters the body from
which it came, and comes back to life again. It then tells the old people of the beautiful things it saw in the ocean--flowers and fishes and animals.
For a long time the people did not know where the Ul'-le or Ghosts went. After a while the Napa Indians told our people that they sometimes heard strange noises in the air overhead, usually in the evening or very early morning, sometimes at night, and more rarely in the daytime. The sounds were sometimes like singing, sometimes like crying, sometimes like calling or scolding--always high up. For a long time they did not know what these noises were, but finally some wise Indians found out that they were the Ghosts of people from the interior passing over on their way to the ocean.
One of our people was a 'Half Doctor'; he knew much medicine and was a good dancer. Once, when some one died, the 'Half Doctor' made up his mind that he would find out about the Ghost. So after dark he went to the place and hid close to the grave and watched. In the night he saw something like a person get up out of the ground and shake his head to shake the earth off, and then fly away quickly, disappearing at once. Nothing more was seen.