The following are important for you to consider bringing so that you enjoy your hike:

A keen interest in nature

To be acclimated to altitude for at least 2-3 days prior

Ample water (1 liter for a 3 hour hike; 2 liters for a 6 hour hike)

Appropriate day hiking gear, to include hiking footwear, clothing, etc. (see Suggestions)

Layers (for sudden weather change)

Small day pack

Energy snacks / lunch 

Sun protection: hat and sunblock 

Insect repellant (summer)

Rain gear (summer)

Optional:

Small notepad and pencil (you may want to jot things down for future reference)

Binoculars (great for seeing birds and other aspects of nature one cannot approach too closely!)

Field guides

Summer Footwear

If your are fairly new to mountain trails know that proper footwear may be the most important item you bring. It is no fun to be far out on the trail only to discover you now have a foot blister or injured ankle - and now you have to either finish the hike or return to the trailhead hours away. Three suggestions: 1.) wear hiking boots 2.) wear boots that rise above the ankle to protect it from injury (twisted ankles are a major cause of mountain trail injury) and 3.) wear boots that have been broken in (meaning you have worn them on and off for at least two weeks prior).

Summer Clothing

Mountain weather is always unpredictable, regardless of what your weather app says. Summer afternoons are notorious for sudden windy rainstorms where the temperatures can drop to uncomfortable levels in a few minutes.. It pays to have some kind of light jacket and/or rain gear. In spring and fall it is a must to layer and be prepared for cold temperatures.