Landeskog was the second overall selection in the June draft, while Siemens was taken at No. 11. They are both scheduled to participate in the Avalanche's training camp this fall.
The 18-year-old Landeskog played last season for the Kitchener Rangers of the Ontario Hockey League. He led the team with 36 goals despite missing a chunk of the season with an ankle injury.
The 17-year-old Siemens suited up in all 72 games for the Saskatoon Blades of the Western Hockey League. The defenceman had five goals and 38 assists to go with 121 penalty minutes.