Weather in the Rockies is unpredictable. Even during the summer months, quick drops in temperature are possible. Regardless of the time of year, weather moves in fast and can sometimes be furious. The first rule of thumb when visiting the heart of the Rockies is to respect the mountains—Mother Nature is in command here, and while we love playing in the snow, it's also important to pay attention to weather brewing over our peaks.

To make sure you're prepared for every possible weather scenario, here's a general check-list of things to pack:

During Summer:
The usual tank tops and shorts, and also:

• Jeans or other long pants.
• Long-sleeve shirts.
• Sweatshirts or a fleece.
• A rain jacket or poncho for frequent afternoon thunderstorms.

During Winter:
Layers. Start with a tight-fitting, breathable, non-cotton under-layer, then build outward with sweatpants, a light sweater or sweatshirt, and top it all off with a fleece that can be worn under an outer waterproof shell.

Lots of socks. Mix in some wool hikers along with your ski socks for the times you just want to walk around the resort.

Snow boots and sneakers.

Waterproof or Water-resistant Snow pants and jackets.

Eye protection. Don't overlook protecting your eyes from the sun, snow-glare and the elements. Goggles and sunglasses are a must for the entire family.

Waterproof mittens or gloves, glove liners, hats and neck gators or scarves. Regardless of how tough you think you are, on snow days you'll definitely want a way to cover your entire face while skiing or riding down the mountain!

Sunscreen and lip balm. Colorado has more than 300 days of sun a year, and at 9,000 feet, you'll definitely need to slather everyone in SPF 30 or higher before enjoying time outdoors.

Baseball hats. Helmet-head can be easily disguised for apres ski with your favorite broken in ball cap.

A small backpack that can be left in a slope-side locker during the day, or that you can wear on the mountain to hold a bottle of water, sunscreen and other daily must-haves.

Helmets (if you're not renting a helmet along with other equipment). Keystone encourages our guests to educate themselves on the benefits and limitations of winter sports helmets. Regardless of whether or not you choose to wear a helmet, every winter sport participant shares responsibility for his or her safety and for that of others using the ski area facilities.

Evening Attire:
Keystone is a quintessential mountain environment. Meaning there aren't any restaurants where jeans, sweaters and general casual wear aren't appropriate attire for dinner. For bars and night spots, jeans will do just fine. Remember that if you plan to walk back to your condo from your favorite night spot, you'll want to bring or wear a knit hat, gloves and a warm coat. As we said above, Mother Nature is the fashion diva in these parts.