South Dakota Trust Company LLC (SDTC) is a state chartered national trust boutique and financial advisory firm founded by Al W. King III and Pierce H. McDowell III. SDTC is an independent trust company, headquartered in Sioux Falls, South Dakota, specializing in providing trust administration to the wealthy, both domestically and internationally. SDTC is a wholly owned subsidiary of Third Constellation LLC, a Delaware LLC, based in New York City.

South Dakota Office:

New York Office:

  South Dakota Trust Company LLC
201 South Phillips Ave. Suite 200
Sioux Falls, SD 57104
(Phone) 605 338-9170
(Fax) 605 274-9200
  South Dakota Planning Company LLC
51 East 42nd St., Suite 306
New York, NY 10017
(Phone) 212 642-8377
(Fax) 212 642-8376