WATER! Bring too much!
Hat
Sunglasses
Dress in layers check the temps before heading out. I would wear an outer rain jacket, a long sleeve tee (nylon), a fleece jacket and 2 pairs of socks. I lived in Gunnison Colorado. I have experienced snow and then temp hitting 90 on the same day during the summer!
Deet bug spray. I forgot when the mosquitoes die off.
Flashlight or even better a headlamp (keeps your hands free).
50ft of parachord.
Multi pocket knife.
Compass & map or GPS.
Maybe another pair of socks. (NO COTTON)
High caloric snack. Avoid the over priced (so called) health bars.

!Remember your burning calories sweating your butt off!

!Study & plan route before going and let others know this route and expected return time!