One of the fires I am most excited about in Colorado is the Mullen Fire, which is actually mostly in Wyoming. This fire is 297 square miles and offers promising habitat. Modern Forager’s burn morel maps have a few new bells and whistles in Colorado and I’m excited to show how we used the additional tools to analyze the fire and create value for hunters this year.

The Making of an “A” Fire

We currently have 31 “A” rated fires across the Western US for 2021 hunting. Colorado itself experienced 36 fires during the 2020 season yet only 5 of them were chosen as “A” fires (and 7 more as “B” Fires). The 2021 burn morel maps have special added information on the A fires, especially those that are massive – and Colorado has several. All of the maps below are available to our members on our Mullen Fire Page. We also have dedicated information on other Colorado wild fires like Williams Fork, Cameron Peak, East Troublesome, and Grizzly Creek.

Public Land

The first thing to look for is public land where it is legal to hunt mushrooms. A good burn has to have plenty of USFS accessible land. The map below shows the Mullen Fire with USFS land shaded in light green… Pretty much the whole fire. Zooming in will reveal some spots with no green filters (private) and some blue filters (state). 


Road Access

The next question is whether this public land is accessible, preferably with good roads running through the burn and even trails. The map below shows lots of roads. It also shows two of the “focus” areas that we will be honing in on.



Trees are a big part of the equation. Burn morels favor certain types of habitats and trees. I look at the burn from satellite view and make sure heavy tree structure exists, the heavier the better. As the map below demonstrates, there are lots of trees. I’ll break down the trees themselves further down this page.


The Mullen Fire Map

Based on a thorough review of all 36 Colorado fires, I selected 5 that were “A” and 7 that were “B.” It’s worth pointing out that the 2019 fires never produced morels due to the 2020 drought, so last year’s maps may be worth a visit too. These 12 fires are included on an interactive map that allows every member access to a Google Topo, Google Satellite, USGS and USFS view of the map. You will also find some of our guidance for each A burn as well as access to all (uncurated) fire perimeters in the state.

This is the main Mullen Fire map for members. You can see we have called attention to two specific focus areas.  Lets talk about that…

click the white square top right of map to view in entire screen mode, esc to exit

A 190,000 Acre Fire

One of the biggest challenges for a new burn morel hunter is partly what burns to focus on. Our fire ranking system provides huge value and a helping hand here. We’ve already done the research to show you the top burns in the state. Your next challenge is where do you start in such a BIG burn?

Purchase 2021 Burn Morel Maps >

Slope Angle and Tree Cover

I like look at a fire initially and assess two things: slope angle and tree cover. First, I am looking for areas that are going to be easier to pick because they are not too steep. It is true that morels love steep slopes! However, we prefer not to hunt steep slopes when avoidable – very tough on the feet. Using our standard base maps it’s easy to evaluate “slope angle” by looking at the topo-lines – the wider the spacing between topo lines the gentler the slope. Likewise, the pre-burned trees can easily be eyeballed via the satellite view map tab at top left. Promising habitat means fairly dense mixed-conifer forests. 

Here are few more interesting maps:

  • Map #1 – This is the Mullen fire with a gray “screen” that greys out all the territory above a 30% slope. This shows good news, most of the fire is pretty walkable.
  • Map #2 – Shows the Mullen fire with additional slope shading in gradient from clear, to green to yellow is 0% to 20% to 28% slope.  
  • Map #3 – Shows a simple forest screen of 50%. This screens out any land with 50% or less forest cover. This is a brute-force tool, but, does allow us to quickly find spots that are more heavily treed.

Setting up slope angle and tree coverage screens can help analyze large burns more quickly. Check out our video for our members on how to do it yourself.

Elevation Study

Elevation is a super-critical component to burn morel map study.

  1. As the season progresses in Colorado, morels move up in elevation. Large burns might have good habitat at different elevation ranges making them good for early, mid and late-season hunts. If you are looking in May you will need a lower elevation than June! Higher elevations might not fruit until late in June or July.
  2. Trees are also very elevation dependent. In Colorado specifically, we often see our favored mixed-conifer forest (Spruce/Fir/Pine/Doug Fir) start at about 8K and really shine above 9K. This also means that early season hunting has limited opportunities. We do look to the Ponderosas/Doug Fir mix in lower elevations for early season hunting though. 

The Mullen Fire starts at 7,566′ and goes as high as 10,147′.  The average is a nice 8,727′. 

Using Gradients

This map shows a gradient screen from 8k to 9K to 10K using blue to red to yellow (highest). Because we screened out the color to 30% (so the underling map is still visible) the blue may render as light purple and the red looks orangey. The bits below 8K and above 10K render with no color.  

If you compare the northern and southern focus zones, you will see they are higher in elevation. The northern focus zone goes from 8,771′ to 10,261′ (Averaging 9,638′) and is decidedly more yellow than the southern focus zone which is more of red/orange and goes from 8,424′ to 9,325′ (averaging 8,959′) in elevation. This suggests the southern zone should pick several weeks earlier than the northern zone.

Elevation gradients are very helpful in burn maps study, Members – check out our video in your dashboard on how to create gradients yourself.


Tree Maps

Tree maps are another new piece of information we are selectively adding to some fires this year.  

  1. Pine – The first map shows pine (lodgepole) which is spread throughout the Mullen Fire. Pine is my least-favorite conifer to find morels in, I prefer a mixed forest with other conifer species. Pine is also often beetle-killed which means there are 10-year old dead trees in the forest which can cause a HOT burn. Fire areas that are too hot do not make for good morel hunting habitat.
  2. Doug Fir – You can see that Douglas fir is lightly represented in the fire, often on the steeper slopes along the western edge.
  3. Fir – Fir is often our target-species in Colorado. It begins at about 8K and gets thicker as the elevation goes up, typically blending with pine, spruce and aspen.
  4. Spruce – Spruce is also a target species and really thrives above 9K. We typically see spruce during the mid and late parts of the season.

We provide tree map resources for our members to create their own tree maps.

Burn Severity Analysis

As mentioned, burn severity can have a dramatic impact on morels.

If the fire burns too hot it is a double whammy:

(1) No overstory means the sun dries and heats the ground in an already dry climate. In this scenario the morels will only flush in unusually moist times
(2) No needle layer (duff) over the ash means the ground absorbs heat and dries up more quickly. With no moisture-protecting duff, morels struggle to thrive. Furthermore, when there is no duff, morels can become very “ashy” as the raindrops hits dry ground and splash ash back up onto the mushrooms.


I focus on areas of the forest that have some burn, and some live or half-living trees to create shade and needle cover. Burn severity maps are available for many fires and are a useful reference. Ultimately, though, they are just a guide – nothing beats laying your eyes on the forest and searching for the right habitat.

Permits and Closures

Another critical piece information packaged into our maps is links for permitting and closures. The Mullen fire is located in the Medicine Bow National Forest.  Learn about Closures and Permits here. Currently, the closure information indicates that the burn is open! That is not currently the case with some of the other Colorado fires, these are report in our members area. This information changes regularly, the links will keep you informed. Always check before you hop in the car to go on the hunt.

Permits for the Mullen Fire: Free permits are available at appropriate Ranger stations which allow 1 gallon per day. Commercial permits are $20 and allow 10 gallons in a 7-day period. This information is from the Forest Service website, we recommend you call to confirm – if you find out any other info, please share in comments below.


Precipitation is a dominant factor affecting burn morel abundance. I say precipitation, not rain, because winter snowpack plays a part in that analysis. As I write this article, in February, we’re watching the snow, and then the rain, to determine where and when to go. I am hoping for average or above average CO snowpack especially in early April as the snow at morel elevations begins to melt. Next I monitor rain and rain gauges – Spring rains bode well. Without rains in April, May and June, the morels will underwhelm, like they did in 2020. It takes 30 days for this underground organism to grow unseen sclerotia which produce small primordia and in turn become a pickable mushroom. If the ground gets too dry during that 30-day period, the fruiting doesn’t really happen.

This sample snowpack map shows current snow levels to be close to average or slightly below. This snapshot was taken on February 25th and we have six more weeks of snow coming. Green is above average, white is average, yellows are below average. Our member area includes links to good snow and rain measurement websites to make your research easier.


While 2021 is a promising year for the hunt in Colorado, the single biggest factor will be the weather. It seems like our snowpack this year will be averagish, which is good enough! However, as the snow melts at morel elevations in April (and May), we will need to see a few good rains soak those areas. If we get some rains into June and July, it will be a banner year, like 2019. Check out our precipitation monitoring resources, our Burn Morel Resources, and our Colorado Foraging Workshop for more related information.

Purchase 2021 Burn Morel Maps >

Showing 12 comments
  • Dr. Harold Larsen

    Excellent discussion, Trent! I, too, am hoping for more moisture and a good mushroom season this year.

    • Trent Blizzard

      Thanks Dr Larsen! Fingers crossed – if you want to carpool or meet at a burn this year, stay in touch! Hopefully we will have our vaccinations by the time the season starts.

  • markla

    no clues on when to go??

    • Trent Blizzard

      Mark, damn, you are a tough customer! There are clues in there… you will just have to read it again: Look for the area where I talk about May, June and July.

  • Christian

    I’m from Glenwood! You think grizzly fire will be prominent fire for morels?

    • Trent Blizzard

      Christian, Yes, the Grizzly burn has some good potential! We have lots of info on it for our members in the maps! Hopefully the rains will come in April and May!

  • Andrew M Williams

    Hello, and Thanks for your valuable service!
    Do you send any updates after hunters start finding good spots?
    An app would be great as it could update $$$

  • Ken Buegeleisen

    Nice explanations of all things morel. I’ve been curious about how to identify tree types from satellite images since this is useful for all sorts of mushroom hunting (like Black Trumpets!).
    Buying my map package today, going to the Sierra’s in May.

  • Johnlueders

    Anyone finding any in Mullen fire we were there this weekend june 19 and 20thno luck

    • Mighty

      Went to the mullen fire same time you did. Was extremely dry. nothing. Just scouted today after 7 days of rain and looked at all, I mean all elevations and aspects from hwy 230 to 130. found 12 tomentosas on the very northern perimeter of the burn at exactly 8493ft elevation on a moderate north facing slope. puddles all over the roads, creeks running nicely, and decently wet overall. didn’t even pick them, between 1 and 3 inches tall, gray and still velvety. 2 years ago, on the south side of 230, wife and I picked our limit in 4.5 hours. I fear that the extreme warmup 4 weeks or so ago may have brought soil temps above prime before the rain could get the morels going. the overall environment in the burn just seems… off. I also checked Idaho 2 weeks ago, from Stanley to Cambridge. drought conditions there as well. unfortunately, I ventured all the way from Wisconsin, and this is it for me this year. I may have been swayed to come next week, but other than those dozen, I found no other ones even peaking through the pine duff. anyway, good luck, and if you have any thoughts on this, please reply. my gut usually is right when it comes to morels, and it ain’t feeling it this year for Wyoming and Idaho. later

      • Mighty

        One more thing, I checked creeks and wash outs at all elevations. nothing. only found elf cup fungi near one creek in one 5 by 5 ft area. ???

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