Wis. Stat. § 701.0810: Record keeping and identification of trust property.

(1) A trustee shall keep adequate records of the administration of the trust.

(2) A trustee shall keep trust property separate from the trustee’s own property.

(3) Except as otherwise provided in sub. (4), a trustee shall cause the trust property to be designated so that the interest of the trust, to the extent feasible, appears in records maintained by a party other than a trustee or beneficiary.

(4) If the trustee maintains records clearly indicating the respective interests, a trustee may invest as a whole the property of 2 or more separate trusts.