Much of the present Park lands formed part of the Kylemore Abbey Estate and the Letterfrack Industrial School, the remainder having been owned by private individuals. The southern part of the Park was at one time owned by Richard (Humanity Dick) Martin who helped to form the Society for the Prevention of Cruelty to Animals during the early 19th century. The Park lands are now wholly owned by the State and managed solely for National Park purposes.
The Visitor Centre buildings were formerly the farm buildings belonging to Letterfrack Industrial School, and the Park Office was the school infirmary. These buildings were erected around 1890. The Park's field laboratory is housed behind the Park Office and is used by research students working on various aspects of wildlife in Connemara.
In the past, the Park lands were used for agriculture, mainly as grazing for cattle and sheep. Vegetables were grown on some of the more fertile lowlands. Today, these areas are easliy recognised by the old cultivation ridges and hollows. Several of the bogs in the Park were used extensively as fuel sources, and old turf banks, now disused, are commonly seen.
Many remains of human presence can be seen in the Park. The oldest are megalithic court tombs some 4,000 years old.There is also an early 19th century graveyard about which little is known. Also of that period is Tobar Mweelin, a well which was tapped to supply water to Kylemore Castle around 1870 and is still in use today. Stretches of the old Galway road, in use over a century ago, may still be seen in the northern sections of the Park, but other stretches are obscured by vegetation. Ruined houses, a disused lime kiln, old sheep pens, an ice house, drainage systems and old walls in various parts of the Park, are all evidence of a greater population and more extensive use of these lands in the past.