Even during a normal year, Jacqueline Kim, a stay-at-home mother of two in Encinitas, Calif., is pretty bullish about making travel plans to national parks. She researches trails and sites, and logs on to the websites right when reservations open up. “Six months ahead, I book it, because I know exactly where I want to be,” Mrs. Kim, 48, said. “If you don’t know exactly which trailhead, somebody else is going to get it while you’re thinking about it.”

This winter, because of the limited capacities imposed on venues by the coronavirus pandemic and increased demand for domestic recreation of all kinds (bookings made on the National Park Service’s reservation hub, recreation.gov, increased by 45 percent from 2019 to 2020, according to Kathy Kupper, a park service spokeswoman), there has been even more incentive to be on top of it. At some mountain ski resorts and other outdoor venues, interstate travel restrictions and quarantine requirements are complicating the usual day trips and weekend getaways. Meanwhile, social-distancing measures have reduced availability at skating rinks, recreational areas, adventure parks and other places, leaving many would-be attendees with no place to go.

If you’re preparing for a simple trip down the sledding hill or even a weeklong road trip, the pandemic has added a host of extra considerations. Here’s how to plan this winter for every contingency.

The constantly shifting landscape of the pandemic, and the public health regulations that can vary down to the county level, may make it tough to plan for the future with confidence. While that uncertainty has spurred many venues to offer flexible cancellation policies, it’s all the more reason to start investigating your options early, ensuring you have accounted for potential complications. (Think: A month or more out, and as many as four for longer excursions.)

For Mrs. Kim, whose family trips just this winter included visits to the Grand Canyon (December) and Joshua Tree (February) National Parks, researching was no longer limited to the recreational areas. Before they left, she also investigated the safest places to stop to eat and use the restroom along the way. And she called hotels to learn more about their Covid-19 policies.

“Plan it early and plan well and plan robustly,” said Mirna Mohanraj, a pulmonary and critical care specialist at Mount Sinai Morningside in New York who has written about vacationing safely.

First, if you are crossing state lines, find out if your preferred destination requires you to quarantine or provide a negative coronavirus test result. If you’re eligible for a vaccine in-state, Dr. Mohanraj said, allow two weeks between your second shot and your departure; that’s how long it takes for your immune system to respond.

At ski resorts or other outdoor recreation venues, remember you’ll need to avoid indoor dining and shared equipment, if possible, so inquire about food options and other amenities to figure out what you’ll need to bring with you. (If you don’t own equipment, Dr. Mohanraj said, look into the venue’s procedures for sanitizing its rentals.) At some mountain resorts, on-site child care and ski school are limited, so consider creating a schedule to coordinate who will take their ski or ride days when. A spreadsheet can help keep it all straight, especially if you’re planning multiple days or separate outings.

Whether your destination or planned activity is far or nearby, keep checking back for new updates as your departure date approaches. After reserving accommodations in August and purchasing a season pass in October, Mike French, 34, a grocery store manager, spent significant time preparing for a weeklong snowboarding trip with his wife and two children, ages 2 and 4. They planned to drive the 10 hours to Breckenridge, Colo., from Westwood, Kan., so he looked into how the pandemic would affect child care, food and grocery options, transportation and “what it looks like to be on the mountain,” he said. He also kept tabs on the public health regulations in Summit County, where the resort is. “Do your research,” he recommended, “and get on the social media platforms and ask questions.”

Affiliate groups on Facebook and Twitter feeds for various resort passes and geographic areas are full of helpful tips about crowds and availability, which can help you plan. Local news media and other crowdsourced guides can also point you in the right direction: The St. Louis Post-Dispatch recently published a map of readers’ favorite sledding locations around the city, and the nonprofit group Washington Trails Association’s trip reports provide information about social distancing, mask-wearing and the availability of toilets at trailheads.

By the middle of February, entry tickets to the Ice Castles, a series of large sculptures and structures made out of icicles in Colorado, Utah, Wisconsin and New Hampshire, had already sold out for the month. You may be familiar with the feeling: Seized by inspiration, you log on to get tickets for an attraction only to find that there are none left.

Many venues are operating at 25 or 50 percent capacity to allow for social distancing, so there are fewer spots available. Often, venues also require advance reservations, some of them with specific timed entries. This helps control the flow of visitors and reduce lines at the ticket booth; it also means they fill up, especially on weekends and holidays. But don’t give up: Find out when registration opens up and make sure you’re online then — and don’t forget to sign any waivers online ahead of time.

“What we keep preaching this year is: Know before you go, and plan ahead,” said Doug Fish, the president and founder of Indy Pass, which grants access to 61 independently owned ski resorts in the United States. Many resorts still require reservations from passholders; if that’s the case, reserve early. “The reservation doesn’t cost anything,” Mr. Fish said, “but they need to know you’re coming.”

If you do nab a reservation for a peak time, congratulations. However, you might find yourself, surprisingly, in a crowd. This is especially true on the ski slopes: Because of social-distancing requirements, most resorts are limiting the number of people from separate households on a chairlift at a time, which has sometimes produced long lines at the base.

Look into reserving an off-peak time, particularly if you give yourself enough lead time to plan for a weekday. You’ll be competing with fewer people to secure tickets, and you’ll run into less congestion. (At some places that don’t require reservations, like parks and other snow-play areas, finding a parking spot can be the limiting factor, which is harder to predict.) Or uncover a new, less-traveled ski area instead of simply visiting your popular home mountain.

“Think outside the box,” said Matthew Bramble, who runs the Northeast Skiology Group on Facebook. “There’s a lot of groupthink going on right now,” he said, adding, “this is a good time to explore.”

Warming tents, welcome centers and base lodges are operating with more limited capacities and hours — if they’re open at all. As a result, there’s been “this kind of revival of the parking lot scene,” said Kristin Rust, a spokeswoman for the Alterra Mountain Company, which manages the popular Ikon Pass.

Preparing your vehicle to take the place of any usual on-site facilities can make more spontaneous (or early-morning, if you’re trying to avoid crowds) departures that much easier. R.V. travel can also be a fun, safe, self-contained option. Catherine Caruso, a spokeswoman for the United States Forest Service in the Pacific Northwest, recommends you pack it with food, water, blankets and extra warm clothing. Backup masks can’t hurt, either — especially for children. Research your route to find out if your drive will require snow chains on your tires or other preparations.

Woody Bousquet, 67, an avid skier and a retired professor at Shenandoah University in Virginia, has taken to bringing a folding chair and welcome mat on his mountain excursions to use to change into his boots. “Your car is your base lodge,” Mr. Bousquet said.

Last spring, Mr. Bousquet bought a pass that would secure him access to the Vermont resorts he and his ski buddies planned to visit in the winter. But in the fall, when Vermont tightened its entry requirements — mandating either a 14-day quarantine or a seven-day quarantine and a negative coronavirus test — Mr. Bousquet realized he would not be able to travel as planned.

Instead, he decided to ski at areas a little closer to home, across the Southeast, that he hadn’t previously considered. Conditions in North Carolina and West Virginia weren’t always ideal, but his chosen sport requires some flexibility. “It’s got to be pretty miserable for me not to ski,” he said.

Have a backup plan, or three. And if you’re traveling with children, prepare them for a little letdown while getting them hyped up about your alternate plans. “This is a time to have a Plan B, C — maybe D,” said Anna Roth, the hiking content manager of Washington Trails Association.

You might even try a new type of recreation: If your home ski mountain is booked up or you can’t make it, go snowshoeing or try another outdoor activity instead. “It’s a great time to try new stuff,” Dr. Mohanraj said. “Be adventurous.”

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