Katahdin Woods and Waters National Monument, Nature reserve in Penobscot County, Maine, US.

Katahdin Woods and Waters National Monument protects 87,563 acres (35,435 ha) of mountains and forest in northern Penobscot County, Maine, including a stretch of the East Branch Penobscot River. At Grand Pitch the river runs over a rocky drop into white water, with dark jagged rocks and moss along the banks and a dense line of pointed evergreens behind. The monument adjoins Baxter State Park on the west.

Roxanne Quimby, co-founder of Burt's Bees, and her foundation Elliotsville Plantation began buying land east of Baxter State Park in 2001 and announced plans for a national park in 2011. After political opposition, she pursued a national monument instead. On 23 August 2016 the land, valued at $60 million, was donated to the federal government with $20 million for operations; President Barack Obama proclaimed the monument on 24 August 2016.

The monument's name and the Tekαkαpimək Contact Station, opened in August 2024, draw on Wabanaki culture and history; the station's design was inspired by it. The Penobscot Nation inhabited the area for more than 11,000 years, and Penobscot guide Joe Polis led Henry David Thoreau through it in 1857.

The monument offers hiking, camping, mountain biking, fishing, hunting, and snowmobiling through a network of trails and facilities. Access is easiest from the northwestern entrance, where visitors can reach most activities and facilities.

At Grand Pitch, a rapid on the East Branch, the monument's oldest rock is exposed: light greenish-gray quartzite and slate about 500 million years old, from the early Cambrian. It belongs to the Weeksboro-Lunksoos Lake anticline, an upward fold of rock that records ancient mountain-building.