On Friday it said it had engaged Protek Norr AB of Sweden to do the work, which consists of between five and seven prioritized drill holes of 125-200 meters in length.
The first holes will target a zone of massive sulphide mineralisation intercepted in historic drilling (1970-era) near the Helenegruvan mine.
The second group of targets will focus on a strong anomaly identified by 2018 ground surveys near the Myrgruvans mine.
"We are very pleased to be commencing our first major drill program in many years," said Jason Gigliotti, the president of Sienna said.
"Our shareholders have been patient and we feel this project has great potential and we are looking forward to what the next few months will return.
"This phase of drilling will provide a strong start to build on the historic data. We are at the early stages of this project and look forward to bringing this project forward with modern approaches and views at a time when the battery metals sector is gaining significant traction globally."
Slattberg's massive sulphide mineralisation is known to be strongly magnetic, owing to its high concentrations of pyrrhotite, a mineral associated with Co-Ni-Cu (cobalt, nickel, copper) mineralisation.
Earlier this month, Sienna significantly increased its acreage at the project, which now consists of three exploration licenses covering 12,733 acres and at least 16 historic mines, with one being the historic Martanberg copper mine, which was operated in the late 1700's and early 1800's.
Slattberg is located 25 kilometers northwest of Falun, Sweden.