The Rocky Mountain National Park is an excellent place to take a bike ride. The three main trails include Bear Lake Road, Horseshoe Park (Estes Park Loop), and Trail Ridge Road. You will need to pay a small, $3 fee per week and stay to the trails provided. Any bicycling on park trails is prohibited.
The only caution provided by park rangers is that because you are at high altitudes and working steep riding trails, you should have the right type of bike and be in good physical condition. Although beautiful and fun, biking in the Rocky Mountains is considered a strenuous exercise. If you decide to take a bike ride, be sure you have a map and let someone know the route you plan to take. Additionally, because temperatures and weather can change so quickly, always be prepared with appropriate clothing, have a snack and water with you, and be careful of slippery trails.
This national park offers 355 miles of trails that wind around lakes, mesmerizing waterfalls, meadows, fields, and some of the most beautiful scenery in the world. For this reason, hiking and backpacking are common activities. The great aspect of hiking here is that trails have been created to match all levels of skill. For instance, if you are just starting out, then you will find a number of easy trails whereas if you were an advanced hiker, challenging trails are available.
If you want to hike the backcountry overnight, then a backcountry permit will be required, which can be obtained through the visitor centers or park rangers along with maps and booklets about guided tours. If you plan to hike in the winter, stay away from areas of deep snow. Not only will you find yourself become extremely fatigued but also, the area is damaged for those that love to cross-country ski. The backpacking during the winter is always fun as the snow begins to fall heavier after the month of September. Just remember that no matter when you backpack or where you go, permit is required.
One very interesting note is that when you do hike or backpack in the winter, if you see pink snow, leave it alone. The pink color is actually created by algae growing in this area. Even more interesting is that the snow tastes very much like watermelon. However, after finding out that it has radioactive chemicals and works very much like a laxative no doubt you will leave it alone.