Montgomery won the New York Bantam Championships in 2002-03 with the Buffalo Selects and attended the USA Hockey Select 14, 15, and 16 camps.
2003-04: Montgomery played for the Syracuse Stars. In 62 games he tallied 35 points (seven goals, 28 assists).
2004-05: Montgomery had a strong debut season for the USA U-17 team. In 55 games, Montgomery recorded 25 points (six goals, 19 assists) and 56 PIM. He also recorded a goal and an assist, helping Team USA finish first in the Four Nations Cup.
2005-06: Montgomery worked hard over the summer to improve his physical condition as he stepped up to the U-18 team. In 59 games, Montgomery recorded 22 points (six goals, 16 assists) and 76 PIMs. He played in all 22 games against NCAA opponents and recorded six points (one goal, five assists) and played a very physical game, leading the team in penalty minutes against NCAA opposition with 45 PIM.
2006-07: Montgomery spent 17 games with Ohio State University (CCHA), where he tallied five points (1g+4a), but opted out of collegiate play for the OHL. In 61 games with the London Knights, he recorded 17 points (1g+16a), not bad for a rookie blue-liner.
2007-08: The London Knights (OHL) defenseman had the best season of his career to date, netting nine goals and 43 points in 63 games, all career-high numbers for Montgomery; his 95 penalty minutes was another high for the D-man. He also suited up for five games with the Lake Erie Monsters (AHL), his first look at professional; he failed to register any points with Lake Erie. He again competed with the US National Team, this time at the WJC.
2008-09: Montgomery appeared in five games with the Lake Erie Monsters (AHL) this season, registering an assist and two minutes in the penalty box. He had better luck with London (OHL), tallying a pair of goals and 36 points in 46 games. Expect to see him with Lake Erie for the 2009-10 season.