Clumps on branches - what are they?

Hello, I have a tree that has brown/black clumps on its branches and I'm not sure what they are or how to remove them. I have enclosed a picture and can send a few others if helpful to help identify the tree and what pests likely target these types of trees. I should mention that this tree is located 5 miles south of Itasca State Park. Thank you in advance for any light you may shed on this topic.