There once was a time when planning a visit to a national park involved little more than choosing the dates and packing the car. Yet as more people discover the parks, it becomes harder to secure campsites, lodging, and even parking. To combat this, it's best to decide what you want to do at the park and then try to schedule your visit for the least-crowded time that is best for those activities. So, if horseback riding is something you want to do, schedule your trip for spring or fall, when the stables are open but the crowds are few.

Luckily, there are more lodging and dining choices in and near the national parks than there were 20 or 25 years ago. At that time, we were happy if we found a restaurant that was clean and served basic American food.

Packing -- When packing, keep in mind that this is a land of extremes, with an often-unforgiving climate and terrain. Those planning to hike or bike should take more drinking water containers than they think they'll need -- experts recommend at least 1 gallon of water per person per day on the trail -- as well as sun block, hats, other protective clothing, and sunglasses with UV protection.

Summer visitors will want to carry rain gear for the typical afternoon thunderstorms, and jackets or sweaters for cool evenings. Winter visitors will not only want warm parkas and hats, but lighter clothing as well -- the bright sun at midday can make it feel like June.

Take a first-aid kit, of course, and make sure it contains tweezers -- very useful for removing cactus spines. Hikers, especially those planning to go into the Narrows at Zion, will appreciate having a walking stick to brace themselves against the sometimes strong currents on the "trail," which is actually more wading than hiking

Supplies -- You'll find most of the groceries and camping supplies you want just outside the park's south entrance at Sol Foods Park Market, 95 Zion Park Blvd. (tel. 435/772-0277; www.solfoods.com). This well-stocked store has a good selection of groceries, including fresh produce, meats, and dairy products, plus a very good deli. It also stocks camping supplies, souvenirs, and digital memory cards; rents DVDs; and has a restaurant. It is open daily year-round, 8am to 10pm in summer with shorter hours at other times. In downtown Springdale, you'll find an even better selection at Sol Foods Downtown Supermarket, which carries conventional groceries plus organic food and gourmet items, at 995 Zion Park Blvd. (tel. 435/772-3100; www.solfoods.com). It's open daily 7am to 11pm. On the south end of Springdale (the opposite side of town from the national park), is the Springdale Fruit Company, 2491 Zion Park Blvd. (tel. 435/772-3222; www.springdalefruit.com), which is open only from mid-March through mid-November (daily 9am-7pm) and sells fresh organic fruits, vegetables, and juices (try the fruit smoothies), plus trail mix and baked goods. It also has a picnic area and free Wi-Fi.

Those in need of outdoor equipment, hiking boots, clothing, sleeping bags, stoves, and the like will find what they need at Zion Outdoor, 868 Zion Park Blvd. (tel. 435/772-0630; www.zionoutdoor.com). Outdoor equipment rentals can be found at Zion Adventure Company, 36 Lion Blvd. (tel. 435/772-1001; www.zionadventures.com); and Zion Rock & Mountain Guides, 1458 Zion Park Blvd. (tel. 435/772-3303; www.zionrockguides.com), which rents and sells. For bike rentals and repairs, stop at Zion Cycles, also at 868 Zion Park Blvd. (tel. 435/772-0400; www.zioncycles.com).

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.