From camping under the stars at Big Bend Ranch to exploring the cypress swamps of Caddo Lake, our state parks are more than part of our natural heritage. They make life better in Texas.But our parks are in trouble. Two years ago, the Legislature cut the budget of the Texas Parks and Wildlife Department (TPWD) by $113 million. More than 100 rangers and other parks and wildlife staff were laid off. Critical repairs to aging bathrooms, campsites and sewage treatment facilities were put off.Twenty three parks had services reduced, and some are now only open on the weekend. Grants to cities to build new parks and playgrounds were mostly eliminated.Then came the heat, drought and wildfires. Visitation to parks, and the associated revenue, dropped amid record-high temperatures and empty lakes. Wildfires destroyed much of Possum Kingdom and Bastrop state parks, including 96 percent of Bastrop's majestic pines.With less revenue and new challenges, TPWD had to scale back even further, suspending operations at the Parrie Haynes Youth Ranch -- a 4,525-acre park on the Lampasas River with miles of horseback riding trails and ropes courses.Now, despite admirable efforts to keep the system afloat given a tight budget, the parks department is at the breaking point. If the Legislature doesn't act to restore funding, some state parks may need to be closed.But none of this had to happen. Sales taxes on sporting goods such as bicycles and camping gear bring in $128 million a year. These funds were established to keep our parks open and well-maintained. However, the Legislature has not allocated the vast majority of these funds to our parks, using them instead for unrelated projects and agencies.We shouldn't have to wonder if we're allowed into nature. Our parks should be open now and in the future.Our state parks let us get a breath of fresh air and preserve Texas history. They protect the clean water we depend on and provide a critical home for wildlife, such as the black bear and the leatherback sea turtle.Tourists from other states are among the 7.7 million people who visited our parks last year, and they spend money in our communities. A study by Texas A&M University researchers found that people spend almost $1 billion every year when they visit the state parks.There are signs the Legislature is starting to get the message. The base budget introduced last week increases parks funding, but not by enough to prevent parks closures. Sen. Craig Estes (R-Wichita Falls) and Rep. Lyle Larson (R-San Antonio) have filed legislation to end the raids of the sporting goods sales tax. And House Speaker Joe Straus has called for an end to these kinds of fund diversions.(Estes' bill, SB 175, would require that the parks get 94 percent of the sporting goods sales tax, and the Historical Commission get 6 percent, as current law provides. Larson's HB 105 would divide that money 50-50 between the parks department and the general fund for fiscal year 2014. For 2015, parks would get 75 percent, the Historical Commission 5 percent and the general fund the rest. The 94-6 split would return after that.)It would be terrible to close our state parks and leave us with fewer places to get outside and hike, spy on herons, egrets and turtles and take fishing and camping trips with our families.We know that open space is too important to sacrifice and nature isn't a luxury to dispose of when times get tough. We hope the Legislature gets that and does right by our parks this session.Luke Metzger is director of Environment Texas, a statewide, citizen-funded advocate for clean air, clean water and open spaces. David Teel is president and CEO of the Texas Travel Industry Association.