There's something for everyone at Yellowstone — history, culture, rare geologic formations and phenomena, stunning scenery, ample wildlife, and outdoor activities too numerous to list (fly fishing, backpacking, and river rafting are just a start). Friendly park staff members are at the ready to answer your questions.

Yellowstone is a place of extremes in geology, topography, and climate. With 80-degree dry summers and frosty winters that make many roads impassable, the time to visit really depends upon whether you like your vacations hot or cold. July and August are the prime tourist months, so be sure to book your accommodations months in advance (many guides recommend a year ahead).

Yellowstone summers are dreamy -- hot, dry, and sunny with temperatures hovering around 75 degrees (get more weather info here). You'll encounter mosquitoes near the water, along with throngs of tourists. Due to the high altitude, dress in layers (including a hat) and apply sunscreen. Spring and fall can be cold, wet, and unpredictable, depending upon melting or falling snow.

You can fly into the following airports year-round: Salt Lake City, UT (SLC), Cody, Wyo. (COD), Jackson, Wyo. (JAC), Bozeman, Mont. (BZN), Billings, Mont. (BIL), and Idaho Falls, ID (IDA). There is no train service to Yellowstone, and the only way to easily get around within the park is by car. A popular option is to fly in to Salt Lake City and rent a car. There are also flights from Salt Lake City to West Yellowstone, Mont. (WYS) from July through September.

Renting or driving your own vehicle to the park is really your only option in order to see all there is to see. Distances might seem small within the park, but traveling on mountain highways takes more time and caution, and there are frequent traffic back-ups on Yellowstone's mostly two-lane roads.

Before you come, review Yellowstone National Park's official website's helpful safety tips. The nonprofit Yellowstone Association is located within park boundaries and offers educational programs and package trips.

The entrance fee for Yellowstone National Park is $25 per non-commercial vehicle (this also includes entry into Grand Teton National Park, south of Yellowstone). For $80 you can get a National Parks and Federal Recreational Lands Pass that's good for one year and allows entrance into any Federal recreation sites that charge an access fee. The nonprofit Yellowstone Association offers special packages for travel to the park, including guided tours to view wildlife. Association members receive discounts on park lodging and goodies at all Yellowstone visitor centers.

• Yellowstone is the world's first national park, established in 1872. It is bigger than Rhode Island and Delaware combined.
• Yellowstone falls within three states: 96 percent in Wyoming, three percent in Montana, and one percent in Idaho.
• Yellowstone is home to seven species of native ungulates, two species of bears, 311 recorded species of birds and 18 species of fish.
• Old Faithful geyser, perhaps the most famous geyser in the world, is located in Yellowstone's Upper Geyser Basin and erupts roughly every 90 minutes.
• There are 950 miles of backcountry trails and 287 backcountry campsites in Yellowstone, most of which are never visited by the majority of the park's tourists.
• Yellowstone is an active volcano and experiences about 2,000 earthquakes each year. Much of the park sits within one of the world's largest calderas.