|East Branch Union River|
|235 feet (70 m)|
|Length||9.4 miles (15.1 km)|
|Progression||E. Br. Union R. – Graham Lake – Union River – Union River Bay|
The Bog River is a river in Hancock County, Maine. From its source () on Sugar Hill in Maine Township 16 M D, the river runs 9.4 miles (15.1 km) northwest to its confluence with the East Branch of the Union River in Osborn.