October Fire In Rocky Mountain National Park

[Tim Smith]

630 acres burned in the area of the Big Thompson headwaters this month in Rocky Mountain National Park. Winds today resulted in more fire activity. It's not out yet.

Trail closures include: "Bear Lake Road remain closed, including the Cub Lake Trail, Fern Lake Trail, Hollowell Park Trail, Bierstadt Trail, Bear Lake to Fern Lake Trail, and all trails south of Trail Ridge Road, including Ute Trail."

The fire is beetle fueled and late in the year, both traits of changes associated with climate change. You can read about the effects of climate change on these things on a board on in the parking lot looking up the valley where the fire is burning.

Not sure how much this will affect the Big Thompson. Maybe someone else has looked at this and knows how many acres are directly in that watershed.

[dave potts]

Sad news. Been there several times. It's a beautiful park.

Dave

[Tim Smith]

It does appear this fire is in the Big Thompson watershed. They're reporting 30% containment today with total acres burned approaching 700 acres.

They're calling it the "Fern Lake" fire.

Here are some pictures of that area from a hike I took there last month.

[ness]

Yeah, it looks like the Fern Lake Trail cuts through the middle of it, and it follows the Big Thompson. Man, that would be tough going for the firefighters.

[Haris122]

Man that place looks beautiful. Hopefully the fire doesn't do much long term damage.

[ness]

Man that place looks beautiful. Hopefully the fire doesn't do much long term damage.

The beetle damage is so bad out there that it is inevitable that these fires will continue. Either way, fire or dead trees, this won't get fixed in my lifetime, which is what *I* consider long term. Maybe not even during my children's lifetimes. There's a piece of me that wants it to go ahead and burn -- get it over with and let it start to heal.

I remember a few years back there was a fire in the north part of the park, and the scientists determined there hadn't been a fire in that particular section since the 1400s. (Fact check me, but I think that's right). I find that amazing, and think it puts some perspective on where we are in all this.

[Tim Smith]

The beetle damage is so bad out there that it is inevitable that these fires will continue. Either way, fire or dead trees, this won't get fixed in my lifetime, which is what *I* consider long term. Maybe not even during my children's lifetimes. There's a piece of me that wants it to go ahead and burn -- get it over with and let it start to heal.

I remember a few years back there was a fire in the north part of the park, and the scientists determined there hadn't been a fire in that particular section since the 1400s. (Fact check me, but I think that's right). I find that amazing, and think it puts some perspective on where we are in all this.

The fire is to about 800 acres now and still at 30% containment.

Right now the National Park System is managing the fire for full suppression, so there won't be any clean slates for the region this time around.

Ness, your point is correct, but the problem with trusting the system to reset is that depending on conditions those forests could be lost for hundreds of years not just a few dozen. The Heyman fire has shown very little recovery and that recovery process is going to be measured in hundreds of years depending on local conditions. With climate change settling in, the recovery won't necessarily recover to the system we had before. That might not matter in terms of fisheries or biodiversity, but that's not clear yet.

One thing we're likely to face in the meantime is that once those steep hill sides are denuded, they're going to start shedding sediment. Below is a picture of the gravel in the Big Thompson. It's a fully free stone river with very little sediment loading.

In contrast, here's the substrate in the Pouder River where the High Park fire has loosened the hillsides and resulted in significant erosion. All those spaces filled between the stones means fewer places for invertebrates to hide, more problems with water quality during high flows, more heat in the water due to lower subsurface flows and more problems finding quality sites to build redds.

That would be a sad fate for the upper Big Thompson, but we may be headed that way for a while. This year 2 different streams I've enjoyed fishing have burned. If this stream ends up sediment clogged, THIS is what we're losing...

[ness]

That last pic looks really sweet, but it's the first one in post #3 that gets my predator instinct going. I hope you fished that spot.

Do you have an idea of how rapidly the ground stabilizes and the siltation slows? I remember seeing pics of the Poudre right after the fire and then a month or so later. It was clearing, but had a way to go. And, I have no idea what rains or next-years snow melt will mean for it.

[moguy1973]

You would think that once the forest takes back hold of the ground and grows back up to stop the erosion, all it would take is a nice downpour or winter melt to flush out a stream like that of it's sediment and return it to what it was. Or does the time it takes to do that destroy the aquatic life in the stream in the meantime so it doesn't get back to what it was? I mean back in the day when people weren't around to fight forest fires, fires occurred around streams like this and they all end up fine and as we see them in their pristine state.

BTW, I've been to "The Pool" in the first picture. Hiked up that trail in waders all the way to Fern Lake to fish. Not fun in waders on a hot summer day...Did catch a lot of greenback cuts though rising up to take caddis on the top...

[Tim Smith]

Sediment budgets work like all other budgets. (Sediment in) - (Sediment out) = (Sediment in the stream). I don't know enough about the upper Big Thompson or the soils there (or soils in general) to have a clear idea how this will play out. I do know fire effects vary from almost nothing to pretty bad. I also know that the forests in RMNP aren't typical of what was there in the past. The amount of standing dead timber there is abnormally high. Fortunately they're expecting precipitation tomorrow and later in the week so maybe thing will wind down soon.

I think part of the problem on the Poudre was that soon after the fires, landslides began. That picture I took on the Poudre was from about a month ago. The river was still running brown with a high sediment load. If that same process begins on the Big Thompson, it could be a problem. I see a lot of high gradient and bare rock at the site of the Fern Lake fire. We'll see.

High flows are going to move a lot of sediment in and out of the system. The low gradient meandering valleys will probably take the biggest hits. Wherever the water slows it will drop much of the sediment it is carrying. The sediment walks down the river in dunes, filling the holes.

I'll be watching this one carefully.