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Ultras · US · TX

Isle du Bois Trail Run

4 Miler · 4 miles
Registration open
Race dateDecember 5, 2026
Start8:30am
Whenin 42 days

Who's going to Isle du Bois Trail Run?

I'm running itPlan your weeks and your aid station times I'm crewingWhen to leave, where to park, at every stop I'm pacing or cheeringAsk your runner for their Out Here link

Free. You can start with nothing.

Official website Entry Notify me if this race changes
Free, and always will be. NavRun makes money from race-day planning for runners who want it, never from this. Ultras change constantly, sometimes the morning of. Always confirm with the race director and the official website before you rely on anything here.
Distance Our math
4 miles The race says “4M Run (1 x ≈4M Loop) | 4M Run (1 x ≈4M Loop)”. We worked the total out from that.
Climb
not checked yet
Descent
not checked yet
High point
not checked yet
Time limit
not checked yet
Aid stations
0
Started
not checked yet
Finished
not checked yet
Finish rate
not checked yet
The course

Where it goes loop

4 Miler starts at 08:30 on Saturday, December 5, 2026, at the Isle du Bois Unit of Ray Roberts Lake State Park.

The race

What this one is

The Isle du Bois Trail Run is held on the east side of Lake Ray Roberts in the Isle du Bois Unit of Ray Roberts Lake State Park, near Pilot Point, Texas, about an hour north of Dallas and Fort Worth. The trails are a mix of well-groomed singletrack with some technical sections with roots and rocks, and the race page puts the gain at less than 1,000 feet for each full loop. Runners choose a 4 mile, 10 mile, 20 mile or 50K distance. If there is significant rain, the race is moved to the Greenbelt trail in the same state park.

Isle du Bois Trail Run was first put on by Endurance Buzz and then picked up by the Denton Area Running Club. Blaze Trails Running now puts it on.

Getting in

Getting in Entry, lottery and what the race asks of you before race day.

Lottery
not checked yet
Lottery opens
not checked yet
Lottery draw
not checked yet
Field cap
not checked yet
Registration
UltraSignup blazetrails.com
Qualifying
not checked yet
Minimum age
not checked yet
Transfers
Yes ultrasignup.com
Deferrals
not checked yet
Crew access, pacers and drop bags

The rules that shape your day Anything marked "not checked yet" is a gap in what we hold, never a no from the race.

Crew allowed
not checked yet
Vehicles per runner
not checked yet
Pacers
No blazetrails.com
Muling
not checked yet
Drop bags
not checked yet
Cupless
Yes blazetrails.com
Course marking
not checked yet
Night running
not checked yet
Dogs
Not allowed blazetrails.com
Headphones
not checked yet
Crew rules
not checked yet
Pacer rules
Pacers are not allowed for any event. Any participant who runs with someone who has not registered and paid for the event will be disqualified. blazetrails.com
Drop bag rules
not checked yet
Cutoff philosophy
Final cutoff is 5:00 PM: all runners must be off the course by then. blazetrails.com
Same race, other lines

Other distances and other years

What it looks like out there

Somebody has been out there with a camera the tables say the climb is long. these say what long feels like.

2 people have been out there with a camera or a microphone.

Social account

blazetrailsrun

Social account
Social account

Blaze Trails Running

Social account

These are other people's work and we link straight to them. Watching costs nothing and needs no account. More of them: every race we hold, on film.

Add to this page

What you know every one of these is read by a person before it changes anything

Ran this race? Tell the next runner what you know.

Nobody sees it until we have read it. No account, no sign-in.

Leave blank if it applies to the whole race.

Leave blank if it is not about one particular stop.

Optional. Something like “Cal Street, mile 62 to 78”.

Write it the way you would say it to someone at the start line.

Optional, and it decides nothing. It only tells the next runner where this is coming from.

Optional.

Optional, and never shown on the page. Only so we can ask you a question about this note.

Leave this field blank.

See something wrong or out of date? Suggest an edit.

This changes nothing on the page on its own. Somebody checks it against the race first.

Optional. Filled in for you when you start from a specific line on the page.

Copy it as it appears, so we can find it.

The corrected value.

Required. Where it came from: the race email, the runner manual, what you saw on the day.

Optional.

Optional. A screenshot or a photo of the sign works.

Optional, and it decides nothing.

Optional.

Optional, only so we can come back to you about this correction.

Leave blank if it is about the whole race.

Leave blank if it is not about one particular stop.

Leave this field blank.

Seen a course preview or a film of this one? Send it over.

Somebody watches it before it goes anywhere near this page. What we are after is footage of this course, on the ground. If it would be just as true of any other race, it is not this.

Required. A line is plenty. Where the climbs are, what the footing does, what the last twenty miles look like.

Optional, and it decides nothing.

Optional.

Optional, and never shown on the page. Only so we can ask you a question about this one.

A YouTube link, a race report, a photo gallery, whatever it is.

Optional, and we credit them on the page.

Leave this field blank.

Have the GPX? Send us the link.

We want the address of the file the race publishes, not the file. We download it from there so the page can say where the line came from.

The page or file on the race's own site.

Optional, and only so we can ask you a question about it.

Are you the race director? Get in touch and we'll make it right.

We read every one of these and we write back. Every fact here carries the source it came from, and the way a wrong one gets fixed is a person checking it against what you tell us.

Required, because this is a conversation and we write back.

Tell us what is wrong, out of date, or missing on this page. We read every one of these and we will get back to you.

Optional.

So we know who we are writing back to.

Optional. Director, assistant, comms, whoever you are.

Leave this field blank.

Where this came from. Every fact on this page records its source and when we last checked it: 38 sources for this race. Hover a source link to read the sentence it came from.
21% of what we track for a course is filled in. The rest says "not checked yet" rather than guessing.
See something wrong or out of date? Suggest an edit
Ran this race? Tell the next runner what you know
Were you out there? Say which stops a text got out from
Got footage of this course? Send us the link
Are you the race director? Get in touch and we'll make it right.
Anything else: [email protected]

Ultras change. We will tell you when this one does.

Cutoffs move, races get postponed, lotteries open and close. We read the race's own sources and record where every fact came from. Put your email in and we will send you what changed, and where we read it.

No account, and nothing to cancel.

What happens to your email. Nothing else. I do not sell it, and I will not send you anything except this race changing. One click gets you out.

I keep this catalog because the information is scattered and hard to trust. Telling you when it moves is the same job.

Ultras change. We will tell you when this one does.

Cutoffs move, races get postponed, lotteries open and close. We read the race's own sources and record where every fact came from. Put your email in and we will send you what changed, and where we read it.

No account, and nothing to cancel.

What happens to your email. Nothing else. I do not sell it, and I will not send you anything except this race changing. One click gets you out.

I keep this catalog because the information is scattered and hard to trust. Telling you when it moves is the same job.