Considering the 3 people who died in Oregon,

here is my list (in addition to your photo gear):

1. GPS system. You do not need a fansy one. Just one with longitude and latitude reading should be good enough.

2. Cell phone. Turn it off during normal time to preserve battery for emergencies.

3. Walkie Talkie. Get one that has 12 mile range (or more).

So in the event of getting lost (or injured), you can use GPS to get your accurate location. Then use your cell phone to call for help. If it is out of range, use walkie talkie (truck drivers love to talk on talkie talkies).