The Union River is a river located in the state of Maine, USA. It flows approximately 20 miles from Union Lake to the Penobscot Bay, providing a natural habitat for various wildlife and supporting local ecosystems. The river is known for its scenic beauty and recreational opportunities, including fishing, kayaking, and hiking along its banks. The river's watershed is part of the larger Penobscot River system, which plays a crucial role in the region's ecology and economy. The Union River is also significant for local communities, as it offers resources for tourism and outdoor activities, contributing to the area's cultural and economic vitality.