As with any wilderness destination, take the necessary safety precautions to minimize the chances of injury or death. The high altitudes and severe terrain of the park promote unpredictable weather---especially above the treeline. (Most hiking trails begin above 7,000 feet.) You'll need a good topographic map for any outing. Hook up with a guided backpacking trip if you're a novice or are unsure of the environment.
Backcountry campers in Rocky Mountain National Park need a permit, available at the Beaver Meadows or Kawuneeche visitors centers and reservable in person, by mail or over the phone.
Be careful to comply with all park regulations concerning backcountry camping, which are many to protect both you and the area's natural resources. Campers may camp at designated sites, in the designated cross-country or winter zones, at stock sites or, if a permit-holding technical climber, in bivouac areas. Each has its own specifications: For example, winter campers in the designated winter zone must pitch their tents a mile or more from the trailhead and at least 200 feet from water, invisible and inaudible from designated trails and fellow visitors and only directly on snow or rock. If more than four inches of snow obscure the designated site, campers must set up 200 feet or more away.
Off maintained trails, take care not to damage fragile groundcover, especially in alpine areas. The Park Service reports that plants in the mountain tundra may require a century to grow but one inch---and trampling by hiking boots can set them back or destroy them. Where possible, leap from rock to rock. In groups, spread out so your impact will be less concentrated. Backcountry camping party size is limited depending on season, activity and location; check the park website or contact its staff directly for more information.
In the Rocky Mountain National Park backcountry, you should plan on using a backpacker's stove to prepare meals. Leave precious downed timber to release its nutrients in the ecosystem. In many popular backpacking areas above the treeline, there isn't much available wood to begin with---and heavy use by campers puts even greater stress on this biomass resource. A few designated backcountry campsites have metal fire rings where campfires are permitted, but, in general, use your efficient stove instead.
Black bears and mountain lions may be encountered anywhere in the backcountry, so campers should familiarize themselves with proper safety procedures in the event of a confrontation. Usually, both bears and lions---typically retiring and elusive---may be warded off by standing your ground and making noise. Maintaining a clean camp, which includes properly disposing of food scraps, lessens the chances that a bear---or any number of smaller creatures---will visit. You should hang your gear off the ground to prevent salt-hungry bighorn sheep, deer and porcupines from damaging it.