May 2020
Callahan completed his sixth year as head coach of the Dartmouth men's lacrosse team in 2020.
| Year |
W-L |
| 2015 |
5-8 |
| 2016 |
1-13 |
| 2017 |
2-11 |
| 2018 |
2-11 |
| 2019 |
2-11 |
| 2020 |
3-1 |
| Total |
15-55 |
2020: Dartmouth had a record of 3-1 before the season was ended due to COVID-19. Opening 2020 with wins over Merrimack, Bryant and UMass Lowell gave the Big Green their best start since 2006. After the campaign was ended, Mitchell Myers was named to College Crosse's All-Freshmen Honorable Mention Team. Ben Martin was named Academic All-Ivy and was selected by the Connecticut Hammerheads in the Major League Lacrosse Draft.
2019: Dartmouth ended the year with a record of 2-11. For the second season in a row, the Big Green defeated Wagner by a score of 11-4 (March 2) and followed that up a few weeks later with an 11-7 defeat of Binghamton (March 16). Peter Rizzotti made it onto the All-Ivy Honorable Mention team and was selected to College Crosse's 2019 All-Freshmen Second Team, while Daniel Hincks was an honorable mention. Ben Martin was tabbed to the Academic All-Ivy Team.
2018: The Big Green wrapped up 2018 by going 2-11 overall. They opened the season on a high note with a 13-12 victory over Canisius at home, with Jack Korzelius scoring the game winner with 1.9 seconds to go in the fourth quarter. Dartmouth's second win was another close one; a 9-8 victory over Wagner two weeks later. At the conclusion of the season, Korzelius was drafted by the Atlanta Blaze with the 56th overall pick, was named Academic All-Ivy and to the All-Ivy second team, along with Austin Meacham.
2017: Dartmouth ended the season with an overall record of 2-11 and an 0-6 mark in Ivy League action. The Big Green picked up their first win of the year in the form of an 11-9 win over Vermont on Feb. 28 and got their second victory on April 11, defeating UMass Lowell by a score of 14-8. At the conclusion of the season, Jack Korzelius was named All-Ivy Second Team, while Austin Meacham was an honorable mention. A few days later, Wiley Osborne and Timmy Burke were two of 75 players to earn selection to the 2017 New England Collegiate Lacrosse Association (NEILA) Academic All-New England Teams.
2016: The Big Green ended up with a record of 1-13 and 0-6 in Ivy League play. On March 19, Dartmouth had a huge 13-12 win over Big10's Michigan on the road during the teams' first-ever meeting. Jack Korzelius was named All-Ivy Honorable Mention for his 17 goals, seven assists and 24 points throughout the season.
2015: During his first season at Dartmouth, Callahan led the Big Green to a record of 5-8 and a conference mark of 1-5, which included a huge 12-11 double-overtime thriller over Harvard to kick off Ivy League play. Phil Hession was named First Team All-Ivy, while Robert Osgood was a second-team selection. Hession was also selected to the NEILA All-New England Second Team for both faceoffs and midfielders, and was named a USILA Scholar All-American.
Callahan came to Hanover after spending seven years as an assistant coach and defensive coordinator at Lehigh. He helped guide Lehigh to three consecutive league championship game appearances (2012-14), back-to-back Patriot League Championships as well as berths in the NCAA Tournament in 2012 and 2013. From 2007-11, he served as the second assistant under head coach Kevin Cassese. His primary duties with the Mountain Hawks were as defensive coordinator, including overseeing the goalkeepers.
Before arriving at Lehigh, Callahan enjoyed a successful four-year career at Stony Brook, serving as captain of the Seawolves and garnering Second-Team All-America East laurels as a goaltender. He was an All-Rookie Team selection in 2004, as well as an STX/USILA All-American after leading the nation in save percentage and goals against average.
Off the field, Callahan was involved in a number of activities, including the Student-Athlete Advisory Committee, the Inter-Collegiate Athletic Board and he was selected by the NCAA to represent Stony Brook at the 2005 NCAA Leadership Conference in Orlando, Florida.
Callahan earned his bachelor's degree in health care management in 2007 and later got his master's degree in education from Lehigh.