classified "for seasonal, recreational, or occasional use". This was the second highest percentage nationwide, after Maine. In some Vermont cities, vacation homes owned by wealthy residents of New England and New York constitute the bulk of all housing stock. According to one estimate, as of 2009, 84% of all houses in Ludlow were owned by out-of-state residents. Other notable vacation-home resorts include Manchester and Stowe. Hunting Hunting is controlled for black bear, wild turkeys, deer, and moose. There are 5,500 bears in the state. The goal is to keep the numbers between 4,500 and 6,000. In 2010, there were about 141,000 deer in the state, which is in range of government goals. However, these are distributed unevenly and when in excess of , negatively impact timber growth. In 2012, hunting of migratory birds was limited to October 13 to December 16. Waterfowl hunting is also controlled by federal law. Skiing and snowmobiling Some of the largest ski areas in New England are located in Vermont. Skiers and snowboarders visit Burke Mountain Ski Area, Bolton Valley, Smugglers' Notch, Killington Ski Resort, Mad River Glen, Stowe Mountain Resort, Cochrans Ski Area, Sugarbush, Stratton, Jay Peak, Okemo, Saskadena Six, Mount Snow, Bromley, and Magic Mountain Ski Area. Summer visitors tour resort towns like Stowe, Manchester, Quechee, Wilmington and Woodstock. The effects of global warming have been predicted to shorten the length of the ski season across Vermont, which would continue the contraction and consolidation of the ski industry in Vermont and threaten individual ski businesses and communities that rely on ski tourism. In winter, Nordic and backcountry skiers visit to travel the length of the state on the Catamount Trail. Several horse shows are annual events. Vermont's state parks, historic sites, museums, golf courses, and new boutique hotels with spas were designed to attract tourists. In 2000–01, there were 4,579,719 skier and snowboarder visits to the state. There were 4,125,082 visits in 2009–2010, a rise from recent years. In 2008, there were 35,000 members of 138 snowmobiling clubs in Vermont. The combined association of clubs maintains of trail often over private lands. The industry is said to generate "hundreds of millions of dollars worth of business." Quarrying The towns of Rutland and Barre are the traditional centers of marble and granite quarrying and carving in the U.S. For many years Vermont was also the headquarters of the smallest union in the U.S., the