[2] In March 1975, local observers noted a dark column rising from Sherman Crater that sharply contrasted with previous white steam emissions.

[3] As a result of the activity and hazard concerns, all potential monitoring tools available at the time were employed and the Baker Lake reservoir was lowered to accommodate possible lahars.

[3] As time passed, no clear signs of rising magma, significant changes in gas composition or emission rates or surface deformation appeared.

The activity gradually declined over the following two years but the amount of heat escaping from the ground stabilized at a higher level than before 1975.

Field observations and onsite monitoring occurred sporadically in the 1990s and more regularly in the 2000s, which provided for a relatively long-term data set regarding the behavior of Mount Baker.