Ensuring the safety of dams is paramount due to their significant economic worth and essential functions, including providing water for irrigation, generating hydroelectricity and managing floods. Yet, dams can degrade over time, potentially leading to diminished performance or catastrophic failure. Such failures can result in substantial economic losses, environmental calamities and loss of life. To enhance safety, it's crucial to regularly monitor dam performance using Structural Health Monitoring (SHM) techniques. The sporadic dynamic testing of dams has been a valuable method for assessing their structural integrity, aiding engineers in maintenance and safety decisions. However, these tests, typically performed on a case-by-case basis, rely on limited data and fail to capture changes in environmental or operational conditions. Understanding these effects is crucial for accurate assessment and mitigation strategies. To address this gap a study was performed on the Mactaquac Generating Station, utilizing full-scale monitoring data from the Mactaquac Life Achievement Project. An innovative analysis approach successfully identified and tracked modal parameters despite variations in operational and environmental conditions, identifying the first 7 modes over three years of vibration data.