SDCL § 55-2-2: Trustee not to use property for his own benefit--Profit of trustee from use of property, extent of liability.

A trustee may not in any manner use or deal with the trust property for his own profit or for any other purpose unconnected with the trust.

If he does so, he may, at the option of the beneficiary, be required to account for all profits thereby made or to pay the value of the use of the trust property, and if he has disposed thereof, to replace it with its fruits or to account for its proceeds with interest.