As of 2005, 287,500 acres (116,300 ha)[1] or 41 percent of the land within, is owned by the state as part of the Forest Preserve; it is managed by the Department of Environmental Conservation (DEC).

[2] Later it was heavily exploited by the Dutch, English, Irish, and Germans; local industry included logging, bluestone quarrying, leather tanning, wintergreen and blueberry harvesting, trapping, fishing, and later, tourism.

The old-growth hemlock and northern hardwood forests on the steep mountainsides and remote valleys were sufficiently inaccessible that they survived the logging, tanbarking and charcoal industries of the 18th and 19th centuries.

The lands, mostly around Slide Mountain had come into the county's possession when loggers looking to extract tannin for use in tanning leather from the bark of the many Eastern hemlocks growing there at the time, took the trees, made their money and then left the region without paying taxes.

That provision was later applied to the Adirondacks as well; it remains in force today and makes the difference between survival and insolvency for many towns and other local governmental entities in both parks.

As the timber industry kept making determined efforts to undermine the bill, its original sponsors took the occasion of New York adopting a new constitution in 1894 to enshrine it in that document, with language that plugged all the loopholes that loggers and officials on the state's Forest Preserve Advisory Board had been using.

In 1892, the state spent $250 to build a trail up Slide Mountain, which had only recently been proven by Arnold Henry Guyot to be the range's highest peak and was thus attracting a great deal of tourist interest.

But this Blue Line used not existing municipal boundaries but the old Hardenbergh Patent survey lots, watercourses and railroad rights-of-way, creating a finer, more focused park that gave some of the towns on its periphery areas where they could be assured land would not be subject to Article 14.

Bond issues approved by voters in 1916 and 1924 for a total of $12.5 million led ultimately to the addition of 121,000 acres (49,000 ha; 490 km2) to the state's holdings.

The economic collapse of the late 1920s and 1930s made a lot of desirable land available at low prices, and with the notably aggressive Robert Moses in charge of the state parks, valuable properties like the Devil's Path Range, the summit of Slide Mountain and Windham High Peak became part of the Forest Preserve.

However, the trails built by the state rapidly fell into disuse, Raymond H. Torrey would note by the end of the decade as what hikers there were tended to bypass the Catskills in favor of the Adirondacks and higher peaks in northern New England.

In 1957, the Blue Line had expanded to its present configuration, taking in not only the lands almost to the Kingston city limit and Thruway at the east, but more of Sullivan and Delaware counties in the west.

By the early 1970s, the Borscht Belt era was ending, as the restrictions on Jewish guests at other hotels and resorts that had given rise to it fell victim to civil rights laws, and younger generations of Jews in any event felt more assimilated than their parents and grandparents had.

While the commission considered the same recommendation for the Catskills, it ultimately decided against it in its final report in 1975 (it did try to promulgate a master land use plan, but that was rejected).

What it did recommend was a master plan for the state land in the Forest Preserve, important since management was divided (and still is) between two different DEC regions, which had never been on the same page nor known what the other was doing.

DEC got busy finally clarifying what user groups (in addition to hikers, snowmobilers, horseback riders and cross-country skiers) were allowed on which trails, and marking them appropriately.

Advocates for the Catskills wanted to build an Interpretive Center, that would educate visitors about the park and its purpose, as a focus for regional tourism.

The Palisades Interstate Park Commission was to operate it (to get around the restrictions of Article 14) and the New York–New Jersey Trail Conference made plans to route the Long Path past it.

The site, locally referred to as the "road to nowhere," was maintained, but had little to do except stop and picnic and follow the short nature trail that has been cut through the nearby woods.

Also in 1999, Governor Pataki designated most of the summits of the High Peaks as Bird Conservation Areas, in recognition of the importance of their boreal forests as summer habitat for Bicknell's thrush, only recently declared to be a separate species.

Under the Master Plan, all state land in the Catskills is organized into contiguous management units falling under one of four categories: Wilderness, Wild Forest, Intensive Use or Administrative.

No artificially-powered devices are permitted to be used in wilderness areas – chainsaws may only be used to clear trails with express written authorization from the DEC commissioner, and vehicle usage is forbidden in all save dire emergency circumstances.

It has also been informal DEC policy to treat all lands in its possession in the Catskill Park above 3,100 feet (944 m) in elevation as de facto wilderness.

Hunters also find them desirable as the second- and third-growth forests in the area are more likely to contain deer and the carcass of the taken animal can be driven out of the woods instead of being walked out.

A similar solution has been proposed under the new Master Plan to continue to allow more active use of the Hunter Mountain fire tower and the road leading up to it.

Tremper, Shandaken and Sundown in Ulster and the Blackhead, Colgate Lake, Hunter Mountain, Kaaterskill, North Point and Windham High Peak Wild Forests.

In addition to redesignating a good portion of those areas as wilderness, the proposed update would consolidate some into larger units (all the Delaware County properties, for instance).

The campgrounds are generally far smaller units, with many sites and basic facilities available, sometimes abutting wilderness and wild forest areas, and paved roads offering easy vehicle access.