The operator of the dirt bike, 22-year-old Carlos Colon of Holyoke, was found dead when emergency crews arrived.
The victim was found in a wooded area along East Mountain Road after police say his bike collided with another dirt bike.
Also injured in the crash was 32-year-old Luis Gonzalez from Holyoke. He was taken to Baystate Medical Center and is listed in critical condition at this time.
An investigation into the accident is ongoing by Mass. Environmental Police.