Not specifically a bug out bag, but here's some of the 'emergencies' that I have run into while in a 4x4 in the woods and what I needed:

1. a stick on the trail rocked up from underneath my truck and broke my fanbelt (yes, even with my factory installed skidplates). Needed a spare fanbelt and hand tools
2. Sharp rock lacerated my fuel tank, needed a sheet metal screw,a washer, a screw driver, and a rubber patch...used a slice of rubber off of the sole of my shoe
3. got high-centered on a concrete firetower pylon concealed in high grass (long story). Needed high lift jack with proper attachments for the vehicle, and some logs for under the wheels.
4. got stuck in backwoods river mud. Needed a hatchet and a jack to cut brush for a base for the tires.
5. tree fell across the backwoods tote road trail in a sudden windstorm. Needed a bowsaw and a tow strap to drag the tree to get out
6. flat tire while parked in a clearing and I was out on a trail. Needed spare and a means for soft-surface jacking.

If you are going to spend a lot of time in the backcountry you should have some robust tools in addition to your survival equipment:

a real shovel (not a little one)
axe, machete, and bowsaw
spare fuses, hoses (esp. lower radiator) and fanbelts
Hi-Lift jack with cover, mount, and proper accessories for your vehicle
heavy nylon snatch strap
good quality lever winch (come-along) or if you have the means, a receiver-mounted winch and a 2" receiver installed in the front and back

I agree with Leo; prioritize your gear; critical items should be on person.

Carrying the PLB in your pocket is a great start. Not everything is critical, but a small kit with an ability to signal for help, start a fire and provide a minimal shelter should be doable. The ditch kit can carry the rest if you have time to grab it.

Now that you are in shoes -- Smartwool socks (REI.com, Backcountry.com, campmor.com ... et al) and Smartwool liners. One set on your feet, and a clean, dry set in the kit. When you need to walk distance, good shoes and socks rule.

$.02

I really like my Kelty Redwing backpack.
http://www.google.com/products/catalog?q=kelty+redwing+backpack&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&tbm=shop&cid=1731160766756873620&sa=X&ei=PXwQTpWEMI-KhQe0vMjqDQ&ved=0CG4Q8wIwAw

Big enough for a 3-day bag, actually rides well, I think it's well organized and reasonable at about $60. One of my medics uses that Molle 3 and it seems OK, but maybe a smidge small. Then again, I tend to pack a bit...

If you're planning a trip up to AK, check out expeditionportal.com Probably better suited in some ways to your trip; there are several after action reports on people driving through the state.

We have been doing similar back country travel for years. Only we have a lance pick-up camper on a 1 ton 4x4.

I found that the only way I could carry enough stuff on my person is by using a mollie vest. It is comfortable to drive in, easy to put on and take off and most important, I can put the pockets where I want them.

It took me awhile to work out a suitable configuration for my situation. I change it a bit now and then as situations change but mostly it works just fine.

I carry a PLB, Driod, Pistol (as needed), knife, small tool set, survival gear, water, food and assorted other stuff. I have several pouches that I can add when doing specific tasks.

When I go for even a short walk, I stuff some items in pouches that I keep empty when in the vehicle.

The vest cost about $12 at a surplus store someplace. However the pouches run $8-15 and I have a whole bunch, so the cost does accumulate. The vest alone has no pouches, just the web attachment system. It adjusts to any size and has no back, and mesh front panels so it is comfortable to wear even in desert heat.

The trick is not to try to carry too much stuff. But because it is modular, one can keep adjusting the load until it is comfortable and efficient.

Nomad

Phone number to sat phone entered into your PLB registration record?

Any risk of it getting wet? Perhaps something water tight to put it into? Extra Battery?

A few things I do with my sat phone are program emergency contact numbers into the phone's phonebook and perform a monthly test call to make sure phone is in working order. Free Iridium test call number is: 1-480-752-5105. Check for and apply latest firmware update? I think the lastest is HT10017.

My idea of a container for a ditch kit is: SwitlikAir Crew vest. You don't necessarily get to pick where the ditch happens -- it might be in a river.

Additional gear can be kept in a dry bag.

Welcome to the forum and great first post.

Most of the others have already gave some good suggestions and your kit contents are very similar to mine for off-road /remote areas. The one thing I would recommend is another water bottle and also pen/pencil and small notebook.

We just returned from a weekend trip that took us over a 100 km (60 miles) from the nearest town (I'll do a separate post on this later.)

While traveling by vehicle or on foot, I keep extensive notes on weather, terrain, GPS coordinates of off road / trail crossings, (including elevation) etc in a small notebook and on the map(s). If we come by major creeks and rivers, I make note of the water, specifically if it is drinkable or not as right now with summer snow melt from the mountains, many of these waterways are so clogged with sediment that water filters will not last long at all. I also keep track of water usage, for example, I recorded 6 liters of drinkable water consumed on Saturday for 2 people.

In the event of injury or vehicle breakdown, having these notes could help in any number of methods if we are forced to wait for help (PLB equipped) or walk out.

Welcome to ETS!

I'd suggest that you carry a PSK (personal survival kit) on your person. Mine is a Doug Ritter PSP+ with a mini-Bic (secured with a cable tie) and a 2-person Heatsheets. Your knife and pistol (if you're carrying one) should also be on-body.

Preferably in a location that's not going to REALLY hurt if you roll. Ie, on a hip or in a crotch pocket.

The military puts us through a "roll-over" trainer for the Hum-vees and other things. Really fun when the M4 whacks you in the face.

You could consider duplicating some of the equipment in your kit. Have your main kit in the front with you, have a secondary (partially duplicated) kit stored in the back of the vehicle, near the tail gate.

From what I’ve read, some fires start under the engine (or exhaust), even after the vehicle has stopped. Sometimes people have a few seconds to open the back of the vehicle and grab a few items before the vehicle is engulfed, so it may be worth having a small bag there too ? When we travel I have the SPOT in the front and the Sat Phone in the back, in the event of a collision or a theft, hopefully we would not lose both.