All of what we know today as Chevin Forest Park would still have been in private ownership at the start of this time period. The Danefield Estate was still owned by the Fawkes family, and the Surprise View and White House areas owned by various different families.

But as a result of the two World Wars this situation was about to change.

During the wars, the nearby RAF base (today known as Leeds-Bradford Airport) was a target for enemy aircraft. Shallow, circular depressions can be seen near Shawfield where Beaufort guns and searchlights would have been stationed pointing up into the sky looking for enemy aircraft. A number of bombs were dropped on parts of the Chevin as enemy aircraft sought to lighten their load before returning home. Some of the craters left by these bombs can still be seen to the west of Surprise View near the main path leading to Yorkgate Quarry.

Most of the trees on the Danefield Estate were felled to provide timber for the war effort. A contract dated 1st June 1942 indicated that 1 019 trees were sold to the local timber merchants William Brear and Sons for £2000. Most of the trees felled were Beech (used for rifle butts), Sweet Chestnut (used for railway sleepers) and Oak (used for coffins). This would have been a dramatic impact on the local landscape as these trees first planted by Walter Fawkes in the 1780s were felled.

This is the main reason that most trees on the Danefield Estate today are relatively young, only those trees that escaped this clear-felling are older than 70 years (such as some Sweet Chestnut and Oaks on slopes and along becks).

In August 1944 Major Legender G.W. Horton-Fawkes of Farnley Hall decided to give the Danefield Estate (110 hectares) to the people of Otley. In a letter to Otley Urban District Council he said:

“Your Council may even now be considering alternative forms of war memorials. It occurs to me that an open space which can be beautified by trees and preserved in a natural state might offer an opportunity as a memorial to all who fought and furthered the war of Freedom on all fronts.”

This act of generosity saw the Danefield Estate become open to the public for the first time since the Land Enclosure Acts of the 1780s, and the first steps were taken to create the Chevin Forest Park that we know today.