SDCL § 55-3-4: Declaration of trust--Declarations of trustor to trustee before acceptance.

The nature, extent, and object of a trust are expressed in the declaration of trust.

All declarations of a trustor to his trustees in relation to the trust, before its acceptance by the trustees or any of them are to be deemed part of the declaration of the trust, except that when a declaration of trust is made in writing all previous declarations by the same trustor are merged therein.