top of page

The Last 100 Feet

by David Karplus, former OTFSC Treasurer 

(from 2017)

Installment 1

Last100 - 1B.JPG

Every time there’s a fire in California, my out-of-state relatives call and ask, “Are you OK? We hear there are fires in California!” 

My usual answer is “We’re just fine. California’s big. The fires are in San Diego (or Santa Barbara, or Butte, or Yosemite, or…). That’s 250 miles away!” And they are reassured.

Of course, last year, the Rough Fire was just a mile from my house – and a lot closer to some of yours. It seemed crazy and out of control, and many of us were worried. The natural questions to ask then, are: How far away is safe? And how close is it a disaster for me? 

The last question is easiest to answer: the fire is a disaster when it actually burns up my shop … or my house …or my family. Until then it’s just a close call.

And that is a wonderful thing. Because almost everything that determines whether my house burns up happens in the last 100 feet before the house – and I have a lot of control over that.

There are lots of resources out there to give advice about The Last 100 Feet – your Defensible Space, or Home Ignition Zone (here’s one: ). 

This is the first in a series of short articles talking about how fire behaves in The Last 100 Feet, and what you can do to make sure that no matter what happens 250 miles away, or 2.5 miles away, or 250 feet away, it’s just a close call for you.

Installment 2


I was driving through Hartland the other day, and passed a house whose owner obviously cared a lot about their fire safety. They had limbed up all the trees around the house 20’, and had cleared away the ground fuels and duff for 40 or 50 feet away from the house and propane tank. The building had T-111 siding and a metal roof.

And then I saw the pile of firewood and limbs stacked against the bottom of one of the walls – sort of like kindling under a campfire. Not a terribly big stack – just what someone had cleared away from under the trees this year, it looked like. And it’s easy to think that’s not a big deal, since a fire coming through the woods would never get that close to the house across 50 feet of bare ground.

But the fire doesn’t have to crawl across the ground. Wind blown embers – “firebrands” – blow off the fire and can travel hundreds of feet. In the Rough Fire, spot fires caused by embers were sometimes a half mile ahead of the fire.

The most important part of The Last 100 Feet is The Last One Foot. After that comes The Last 10 Feet, then The Last 30.  It may be a lot of work to clear a space 100 feet around your house. The good news is that you can get a whole lot of the benefit of defensible space by just clearing fuels away from the last 5-10 feet around your house.

Start close and work further and further out. Before deciding to clear, mow, and weed-whack another 5 acres, look at the areas right next to the house. Pine needles on the roof or gutters? Leaves blown against a wall? Firewood  piled close to the house? Dried up flowers or grass in a planter box? A pallet leaning on the barn? That’s where to start, and it’s a whole lot less work.

Installment 3


When a wild fire is burning towards my land, should I stay to protect my property, or should I run for safety?  That’s an interesting question, which I’ll get back to. 

The first point to recognize, though, is that if the roads are blocked, I really don’t have a choice (and neither does anyone else). That’s why Oak to Timberline is spending all their grant money on clearing trees that could fall across roads, and why the State has set aside $55 million to clear along state highways. If the roads are blocked, residents can’t escape and firefighters can’t get at the fire to stop it.

Now, back to the question: I would feel really awful if my house burned down. My wife and children would feel even worse if I got killed trying to protect a building that I could rebuild if I were alive. And how much can I really get done fighting fire while breathing smoke?

The good news here is that it’s a false choice: you can have it both ways! If you’ve done your work in The Last 100 Feet before the fire, you can do some quick prep, pack up your valuables, and leave to go breathe clean air while the fire burns around and past your house. CalFire has a good brochure about this: 

Notice that if you have NOT done your prep work, you’re stuck with a crummy choice: your property or your life. And if you have not done your prep work, neither you nor 100 firefighters will likely be able to save your property anyway.

What to bring? During the Rough Fire, I remember being told to bring the Five P’s: People, Pets, Prescriptions, Photos, Papers (and Personal Computer and Phone). I took some extra time and packed tools to build a shack to live in if I needed to, prepped my property as well as I could, and left.

Installment 4

Like everyone else around here, I’ve been watching the trees die for the last 4 years, and it’s awful. I wonder what the mountains will look like in 10 years, after the red trees have turned white, or have fallen over, or have burned.

Unlike most people I talk to, the huge swaths of dead trees in the Forest and Park don’t bother me much in terms of wild fire risk. Yes, if a fire starts, it will be impossible to stop in the beetle-killed forest. Yes, during the Rough Fire, beetle killed trees were exploding into flame 100 yards from the fire by radiant heat. Yes, fire will travel faster in the beetle-killed forest.

But that’s all more than a hundred feet away from my house.

For wild fire, I’m worried that dead trees will fall across the roads and block firefighters and escape routes – but CalTrans, County Roads, and Oak to Timberline contractors have been hard at work taking down those trees (thank you, CalFire State Responsibility Area grant funds from our fire fees!). I’m worried that dead trees or their branches will hit power lines and start fires – but PG&E is working hard to take down at least the parts of trees that could hit power lines (and Oak to Timberline has spent $100,000 of PG&E funds to clear out trees in some very dense, explosive stands). And I’m worried about the trees within 100’ of my house – but this winter I’ll be able to work on those

( ).

There are other worries besides fire, of course, like trees and tree parts falling and hitting something I care about. Like how much I’ll miss the green pine forest landscape. But I try not to let the daily view of dead-tree covered mountains distract me from my personal part of the fire safety problem: how to get all the work done of felling dead trees and chipping or burning the slash in my Last 100 Feet. The dead trees in the Forest and Park are a tragedy, but they aren’t going to burn up my house.

Installment 5

Remember the Cerro Grande fire in Los Alamos back in 2000? A wildland fire swept through the town, destroying over 400 homes – 200 of them in a few hours in one evening. The picture in my mind is of a massive forest crown fire destroying the entire community, with nothing that could have stopped it.

But that’s not how it happened. 

The massive crown fire was there: in the hills outside of town. In town, the fire dropped below the canopy and crept along in pine needles, or ignited independently when flying embers landed in flammable spots.  Wood piles next to houses caught on fire, lighting the houses. Pine needles at the bases of walls ignited homes. One house burning would light the next house – and on down the street. Totally destroyed houses were left surrounded by unburned trees and shrubs. 

The Grass Valley Fire at Lake Arrowhead in 2007 was the same story, with 199 homes lost. In effect, what started in the hills as a wildland fire became an urban fire once it hit town. Each individual home had vulnerabilities in The Last 100 Feet – often the neighbor’s house 20’ away. The stories are here ( – the last two files at the end of the list)

When does a wildland fire become an urban fire? When homes are close enough to be in each others’ Home Ignition Zones – in each others’ Last 100 Feet. The opposite can also happen: a house fire can become a wildland fire if it can spread across the Last 100 Feet to the brush. 

Taking care of your Last 100 Feet protects you from other people’s fires, and protects everyone else from yours. Working with your neighbors on fire safety when one of you has a structure within 100’ of the property line helps protect both of you. If they won’t clear their fuels, maybe they’ll let you clear it. If you can’t clear your own fuels, maybe they’ll help you in their own interest.

Then we won’t be reading articles 10 and 15 years from now about how 200 homes were lost in the Fresno/Tulare foothills when a wildland fire went urban.

Installment 6

My mother used to say, “Everything goes great when everyone does a little bit more than their fair share.”  I liked that, because I had already noticed that things go really crummy when a group of people are looking to get at least their fair share instead. 

So what is “my fair share”? 

On the doing side, I could make a good argument that “my fair share” is taking care of fire safety in my Last 100 Feet ( Unless my neighbor’s house is closer than 100’, the person that really benefits from it is me

So who else’s share would it be? If I don’t do my fire safe prep work, then firefighters have to spend extra effort defending my home (if it’s even possible), and everyone else has to suffer extra risk, because a house fire at my place could spread into a wildfire that could affect them. 

Anything more than your "fair share" would be great! Here are some ideas:

Helping a neighbor with their fuel clearance if they can’t (or even if they won’t, but will let you!).

Volunteering to help with your local Oak to Timberline Fire Safe Council events, or writing an article for the newsletter.

Serving on the Volunteer Fire Department.

Providing a Fire Department connection for refilling fire engines.

Breaking up fuels on your land beyond the Last 100 Feet. 

On the "getting" side:

We all benefit from the local, state, and federal fire fighting agencies (something like $100 million for the Rough Fire alone).

We all benefit from the county and state road maintenance crews.

We all benefit from the research done to tell us what fire safety is.

We all benefit from CalFire officers enforcing fire safety rules.

We’re all benefitting from the extra funds being spend by CalTrans, County Roads, CalFire, PGE, and others to respond to the current tree mortality.

My mother’s mother used to say, “Two moves is worse than a fire.” If we all do a little bit more than our fair share, maybe we can avoid experiencing either bad outcome ourselves.

Installment 7


It’s obvious that a metal roof is better than an untreated wood shingle roof in case of a fire. But what else is important? Some scientists at the Institute for Business and Home Safety did a fun experiment: they built a full-sized house on a big turntable, using all kinds of different construction. Then they showered it with burning embers and tortured it with a giant radiant heater and watched to see what happened. The pictures are cool!

Wood shingles burned through just from embers falling on them. Asphalt shingle didn’t burn through, even when pine needles the roof torched. Anywhere there were dried leaves or fuel at the base of a wall, the wall started to burn – even if the “wall” was a gable or dormer on top of a roof. Embers blew through unscreened attic vents and started fires inside the attic or crawlspace. Embers even blew through cracks between the roof plywood and the framing holding it up!

Vinyl gutters or metal? With leaves in them, it doesn’t matter! The leaves catch from embers, the vinyl lights on fire, melts and falls to the ground, lighting the wall. The metal doesn’t fall, but the burning leaves light the roof sheathing on fire instead.

Radiant heat is less of a problem. Siding lasted 4-16 minutes before igniting from the huge radiant heater. In real wildfire situations, though, that kind of intense heat only lasts a minute or so (unless a nearby building or woodpile catches on fire or there’s vegetation too close to the house). Sometimes people worry that radiant heat will come into the house through a window and light the furniture or curtains. Apparently that only happens after the frame has burnt or melted enough for the glass to fall out or break.

The take-home lessons from this? Roofing material, vent screening, and clearing fuel away from the house are really important! Especially clearing fuels from gutters and the bases of walls. You may have to wait a bit to replace a wood shingle roof, but screening vents and raking duff away from the walls seems like cheap and easy insurance to me.

Installment 8


Ever wonder what it was like behind the evacuation lines during the Rough Fire? I went to Cedar Grove twice while the fire was burning in the canyon. It was grim: the smoke was so thick that we couldn't usually see more than 50 yards, and what we could see from the road was a landscape that was transformed from huge brush and forest trees to barren black sticks. Windrows of slash where fire fighters had worked to widen the defensible line at the road. Vehicles, hoses, equipment, occasional flames. It was surreal.

But the most memorable thing for me was watching the fire fighters work to prepare buildings and developed areas before the fire hit. It was quick, efficient, and educational.

First: Rake duff and leaves off roofs and gutters.

Second: Pick up any and all movable objects near buildings and drop them 30' away.

Third: Rake the duff 5' away from the bases of walls. If the pile is under 1' tall, leave it. If it's taller, haul it 30' away and dump it.

Fourth: Staple flame-resistant fabric over crawlspaces, door and window openings, and vents to keep embers out.

Guess what I did when I got home, and before I was evacuated? The funny thing is that most of those things can be done any time, and in less of a hurry than when huge smoke clouds are on the horizon.

Installment 9


I like to think I'm the kind of person who would go into a burning building to save someone I love. I also like to think I'm the kind of person who would come back out – alive and having rescued what I want to. But would I go into a burning building to rescue a stranger? A stranger's pet? A stranger's wallet? What if a stranger wanted to pay me to go into his burning home to get his cell phone for him? When is the risk worth the possible gain?

For firefighters responding to a fire in the wildland-urban interface, every house is something they'd like to save. And every house is surrounded by fuel - grass, duff, brush, trees, timber – that is either already burning or could ignite any minute. For them, driving to your house is like one of us entering a burning building: dangerous in itself, and a disaster if they can't get back out.

Part of good defensible space is a safe way to get in and out of your property in case of a fire. This means clearing fuel along your access roads so that you can get out, and firefighters can feel good about going in to protect your home.

Clear vegetation at least 15' wide and high along your driveway. Fix bad spots that could slow down firefighters (and it will be a lot easier for you, too!). Do what you can to make your driveway meet current fire code.

If you've done your defensible space clearing well, the area around your home becomes a safe zone from which the firefighters can fight the oncoming fire. (Like during the Rough Fire, when they used the clear areas around Grant Grove as an anchor for their fire lines.)

One fire department's mission statement is “Prevent Harm. Survive. Be Nice.” Clearing your driveway and the area around your house can help them with all three. And you won't have to pay someone else to go get your cell phone.

Installment 10


I was a buildings maintenance supervisor for a few years, and I've seen a lot of interesting wiring. At the most mysterious one, we could shut off all the breakers in the house, and a drill plugged in would still work – but only grind along slowly. Another one was a friend of mine in Miramonte who ran new wiring to his shop – 12 gauge wire on a 100-amp breaker. The scary part is that my friend said, “It works fine!”

For those of you who are not electricians, the electrical code specifies what size wire to use based on how much current can go through it. If the wire is too small, it heats up like a light bulb filament: a little too much current and it heats up a little, cooking the insulation off the wire over time. A lot too much current and it heats up a lot, melting the insulation quickly and maybe lighting it on fire right away (ever short jumper cables together?) A loose connection or a damaged or corroded spot acts like small wire, with the bad place heating up. When the insulation is finally gone, the wires short, and can easily light a fire almost anywhere.

“It works fine,” really means, “It works fine….. for now.”

When I was a kid, I clearly remember going out to see where a branch had rubbed the insulation off a power line. There was a little flame, a little smoke, and little sparks. Sort of cool, and I walked closer to check it out. Then there was a huge noise and a 15-foot long blast of lightning and flame along the power line. I backed up quickly.

Extension cords strung across driveways? At least put it in pipe to protect it from traffic until you can get real wire run. Branches and brush near power lines? Call the power company if it's their line – get someone to clear it if it's yours. Not sure about your wiring? Call a competent electrician.

Yes, I know electricians are expensive, but compare that cost to the 2015 Valley Fire: 76,000 acres, 1,300 homes destroyed, 4 people dead. It all started with bad wiring in an owner-installed hot tub, which escaped that person's defensible space to become a wildfire.

Installment 11

The other articles all talk about fire in the Last Hundred Feet outside your home. What happens if a fire starts at Foot Zero inside your house?

It turns out that modern furniture made from synthetic fabrics burns really fast! It's about like furnishing your house with gasoline. This video shows why you only have about 2 minutes to escape once a fire starts in your home.

So, just like with your defensible space outside, the trick is to be prepared and get out! Put in smoke detectors and check batteries. Make a plan for how to get out of each room – two ways. Talk about the escape plan with everyone in your house, and practice it! Fire extinguishers can be great – for knocking down flame between you and the outside or buying a few extra seconds to escape – they're not big enough to really put most fires out. Here’s how to make a plan:

Once you're out, check for everyone else, call 911, and stop, drop, and roll if your clothes are on fire. if your defensible space is done well, the fire won't spread easily (no fun being outdoors with a wildland fire starting!) If looks like the fire's going to spread, use your well-cleared driveway to escape the property.

That's it! Good prep in the Last 100 Feet means your home will be safer from a wildfire, and you (and everyone else!) will be safer from a house fire. Good driveways mean you can get out and firefighters can feel good about going in. Planning indoors means you’ll be able to escape even though there's almost no time.

inside fire.png
bottom of page