Beatrix had been a disciple of the land conservation and preservation ideals of her long-time friend and mentor, Canon Hardwicke Rawnsley, the first secretary and founding member of the National Trust for Places of Historic Interest or Natural Beauty. She supported the efforts of the National Trust to preserve not just the places of extraordinary beauty, but those heads of valley and low grazing lands that would be irreparably ruined by development. She was also an authority on the traditional Lakeland crafts, period furniture and stonework.
She restored and preserved the farms that she bought or managed, making sure that each farm house had in it a piece of antique Lakeland furniture. Beatrix was interested in preserving not only the Herdwick sheep, but the way of life of fell farming. In 1930 the Heelises became partners with the National Trust in buying and managing the fell farms included in the large Monk Coniston Estate. It was composed of many farms spread over a wide area of western Lancashire, including the famously beautiful Tarn Hows.
Beatrix became the de facto estate manager for the Trust for seven years until the National Trust could afford to buy most of the property back from her. Her stewardship of these farms earned her wide regard, but she was not without her critics.
She was notable in observing the problems of afforestation, preserving the in-take grazing lands, and husbanding the quarries and timber on these farms. All her farms were stocked with Herdwick sheep and frequently with Galloway cattle.