the process:

One of the simplest forms is thus noted by Schoolcraft:[1]

The Mohawks of New York made a large round hole in which the
body was placed upright or upon its haunches, after which it
was covered with timber, to support the earth which they lay
over, and thereby kept the body from being pressed. They
then raised the earth in a round hill over it. They always
dressed the corpse in all its finery, and put wampum and
other things into the grave with it; and the relations
suffered not grass nor any wood to grow upon the grave, and
frequently visited it and made lamentation.

In Jones[2] is the following interesting account from Lawson[3] of the
burial customs of the Indians formerly inhabiting the Carolinas:

Among the Carolina tribes the burial of the dead was
accompanied with special ceremonies, the expense and
formality attendant upon the funeral according with the rank
of the deceased. The corpse was first placed in a cane
hurdle and deposited in an outhouse made for the purpose,
where it was suffered to remain for a day and a night,
guarded and mourned over by the nearest relatives with
disheveled hair. Those who are to officiate at the funeral
go into the town, and from the backs of the first young men
they meet strip such blankets and matchcoats as they deem
suitable for their purpose. In these the dead body is
wrapped and then covered with two or three mats made of
rushes or cane. The coffin is made of woven reeds or hollow