Despite playing three years in the Rangers minor league system, Coalter was never given a chance to show his stuff at the NHL level. Prior to the 1973-74 season, Gary was traded by the Rangers to the California Golden Seals. Gary spent most of the year with the Seals farm team in Salt Lake, but did make his NHL debut that year, cracking the Seals’ lineup for four games in 1973-74. His call up was a reward for his strong season in the WHL, as he notched a career high 38 goals to go along with 69 points.
Coalter was given his best shot at the NHL in 1974-75. However it wasn't with California, but the Kansas City Scouts, who claimed him in the expansion draft that summer. He appeared in 30 games with the Scouts, scoring 2 goals and 4 assists, while playing the rest of the year in the AHL.
That however proved to be Gary's final appearance in the NHL. He went on to join the Springfield Indians for the 1975-76 campaign and then the NAHL's Maine Nordiques - where he set personal career highs with 54 assists and 85 points in 74 games.
Coalter then played his last two years of pro hockey with the Philadelphia Firebirds of the AHL, hanging up the skates after the 1978-79 season.
Gary's first NHL goal ranks as a personal highlight.
"I actually did score one goal against the Toronto Maple Leafs and that was my hometown. Coming in to play against them and beating them … actually, we beat them in Kansas City. But playing against them was an exciting memory for me."
Gary has been working in the construction industry in the Toronto area after his hockey career.