Plans to plant 50 million trees to create a Northern Forest have been boosted by a £5.7 million government grant.
The 120-mile stretch, which is set to run along the M62, will provide habitat for wildlife including birds and bats and protect species such as the red squirrel.
The Woodland Trust, in partnership with the Community Forest Trust and the five Community Forests, aims to plant woodland totalling 25,000 hectares (62,000 acres), in a project which is forecast to cost £500 million over 25 years.
Currently, just 10% of England is covered by woodland, compared to 31% for France and 37% for Spain. The government has set a 12% coverage goal as part of its growth strategy to meet legally binding targets to cut climate emissions.
The forest is projected to boost the local economy by an estimated £2 billion through tourism, jobs and increasing property value. It is hoped the positive environmental impact of the forest will also help to reduce the economic impact of flooding.
Planting will begin in March at the Woodland Trust's 680-hectare (1,680-acre) Northern Forest flagship site at Smithills, Bolton with a mix of native broadleaf trees such as oaks and conifers including spruce and pine.
Austin Brady, director of conservation at the Woodland Trust, said: "The Northern Forest will accelerate the creation of new woodland and support sustainable management of existing woods right across the area.
"Planting many more trees, woods and forests will deliver a better environment for all - locking up carbon on a large scale, boosting wildlife habitat and greening our towns and cities."
Prime Minister Theresa May told BBC1's The Andrew Marr Show: "We're putting money in this national forest. We will be developing that.
"It's going to take time to plant the millions of trees that will be needed in order to develop this national forest, so this is not a short term thing that's going to happen but the commitment is there."
Environment Secretary Michael Gove said: "Trees are some of our most cherished natural assets and living evidence of our investment for future generations.
"Not only are they a source of beauty and wonder, but a way to manage flood risk, protect precious species and create healthier places for us to work and live.
"This new Northern Forest is an ambitious and exciting project that will create a vast ribbon of woodland cover in northern England stretching from coast to coast, providing a rich habitat for wildlife to thrive, and a natural environment for millions of people to enjoy."