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Mature and Old Growth Forests

Mature northeast hardwood trees with fall foliage in Baxter State Park, Maine
Mature northeast hardwood trees with fall foliage in Baxter State Park, Maine. (USDA Forest Service photo by Andy Gray)

Mature and Old Growth

Mature and old-growth forests offer biological diversity, carbon sequestration, wildlife and fisheries habitat, recreation, soil productivity, water quality and aesthetic beauty. These special forests also reflect diverse tribal, spiritual, and cultural values. While often perceived to be tall trees with a large diameter – such as the giant and now rare Redwoods on the west coast – mature and old-growth forests come in all shapes and sizes and can often be abundant.

Like many of the nation’s forests, mature and old growth is threatened by climate change. The mature and old growth initiative is part of an overarching climate-informed strategy (PDF, 26.1 MB) to change the course of increased wildfires, combat climate-related impacts and help retain carbon. This effort also responds to Executive Order 14072, Strengthening the Nation’s Forests, Communities, and Local Economies, issued by the Biden Administration on April 22, 2022. In addition, this and subsequent work on old-growth and mature forests supports the Wildfire Crisis Strategy.

What's New

On December 19, 2023, the U.S. Department of Agriculture published a Notice of Intent in the Federal Register to prepare an Environmental Impact Statement to amend all 128 national forest land management plans to include consistent direction to manage, conserve and steward old-growth forest conditions. The agency is using data identified in the definition and inventory and the threat analysis process to prepare an Environmental Impact Statement.


Executive Order 14072 requires the U.S. Departments of Agriculture’s Forest Service and the Department of the Interior’s Bureau of Land Management (BLM) to:

  • coordinate conservation and wildfire risk reduction activities,

  • define mature and old-growth forests on federal lands,

  • complete an inventory and make it publicly available,

  • identify threats to mature and old-growth forests,

  • develop policies to address threats,

  • develop Agency-specific reforestation goals by 2030,

  • develop climate-informed reforestation plan,

  • develop recommendations for community-led local and regional economic development opportunities.

The executive order reiterates the administration’s policy regarding consultation with state, local, tribal, and territorial governments as well as the private sector, nonprofit organizations, and the scientific community. The interagency mature and old growth initiative began in July 2022 with a Federal Register Notice and public comment period resulting in roughly 4,000 responses and more than 100,000 signatures on various form letters from across the country.

To date, the agencies have held 26 virtual stakeholder sessions with members of the public, employees, and stakeholders along with three virtual engagements for Tribes and Alaska Native Corporations. The tribal consultation period remains open. Engagement with and input from these diverse audiences has greatly helped inform the way forward.

Definitions and Initial Inventory

The definitions for and an initial inventory of mature and old-growth forests on Forest Service lands, released on April 20, 2023, will help guide local land management efforts to steward these forests for generations to come. This initial inventory framework resulted in the Forest Service identifying an estimated 24.7 million acres of old-growth and 68.1 million acres of mature forest representing just over 17 percent and 47 percent of the 144.3 million total forested acres of National Forest System lands, respectively.

  • Full details are available in a technical report (PDF, 1.21 MB).

  • A national map of mature and old growth forests on Forest Service land is available in the Climate Risk Viewer.

The Forest Service and BLM are exploring additional technologies alongside partners and the science community to gather aerial and satellite imagery to map mature and old growth at finer, more resolute scales and create a long-term monitoring system.

Threat Analysis

The Forest Service and BLM have completed an initial threat analysis for mature and old-growth forests and are drafting a report for publication in the coming months.  An introductory threat assessment report (PDF, 10.94 MB) was produced to provide an overview of the forthcoming report.

The threat analysis addressed the durability, distribution, and redundancy of mature and old-growth forests considering threats like wildfire, insects, disease and changing climate and provides information for climate-informed stewardship of these forests. The Forest Service and BLM held several virtual engagement sessions in early November 2023 to discuss their initial findings.

Through the definition, inventory and threat analysis work, the Forest Service and BLM better understand where these forests are located, how much mature and old growth exists, and their vulnerability to threats.

Additional Resources

For questions and requests for additional resources, please email