Pomeroy is notable for being the first American competitor to win an overall victory in an FIM Motocross World Championship Grand Prix race.

[3][5] Pomeroy began to race professionally in Canada to circumvent the American Motorcyclist Association's 18-year-old age restriction and ended up winning the Western Canadian Championship.

[6][10] In the early 1970s, European riders still dominated the sport of motocross and Americans weren't considered as talented due to their relative lack of experience in the nascent motorsport.

[2] Pomeroy arrived in Europe as an unknown and then proceeded to shock the motorcycle world by riding his privateer Bultaco to an upset victory in the 1973 250cc Spanish motocross Grand Prix.

[13] The news of his unexpected victory created a huge wave of excitement in the American motorcycle community where motocross was undergoing an explosive growth in popularity.

[3][13] The Bultaco factory promptly hired him to remain in Europe to compete in the 250cc motocross world championship where he placed seventh in the season final points standings.

[6] Despite his equipment problems, he finished the series as the top ranked American rider, placing fourth against a strong field of European competitors.

[6] He also posted another impressive result at the 1975 Trophée des Nations where he became the first American competitor to win a moto outright in the event, defeating the reigning 500cc world champion, Roger De Coster.

[26][27][28] In 2018 Pomeroy was the winner in a Readers’ Choice vote for induction with the inaugural class of the Central Washington Sports Hall of Fame.