First of all, call it the golden swamp bird or golden swamp warbler (GSB or GSW for short).
Prothonotary warbler, during breeding season, can be found easily on the boardwalks of Battle Creek Swamp and Patuxent River Park - Jug Bay Natural Area if you are still looking for them.
Regarding monitoring Ash trees and their decline, you may find this video from the state helpful https://www.youtube.com/watch?v=OBswH8rF1pQ
Prothonotary warbler, during breeding season, can be found easily on the boardwalks of Battle Creek Swamp and Patuxent River Park - Jug Bay Natural Area if you are still looking for them.
Regarding monitoring Ash trees and their decline, you may find this video from the state helpful https://www.youtube.com/watch?v=OBswH8rF1pQ