A rattlesnake is easily identified by its triangular-shaped head and the rattles on its tail, which gives you an obvious warning if you come near them, and they feel threatened.
Adult rattlesnakes usually won't emerge until April; however, it is sometimes possible to find a baby rattlesnake at lower elevations in any season. A baby rattlesnake may or may not have rattles, it may have a "button" on the tip of its tail, but it can be just as dangerous as its adult parent.
If you hike much, you will eventually encounter a rattlesnake. If you pay close attention to where you are stepping and don't pick up or try to torment the snake, you will probably be okay.
If You See A Rattler
Avoid it. Do not attempt to kill it. Usually the snake will move away from the trail - give it a few minutes to do that.