Dinosaur Valley Endurance Run

at Dinosaur Valley State Park

100 Mile / 100K / 50K / Half Marathon / 5 Mile




We are forced to use Alternate Course B for 2018. Please see the Runners' Manual which overwrites whatever is on this page.


The race is held at the beautiful Dinosaur Valley State Park in Glen Rose, Texas. This course has rolling and sustained ascents and descents, although none are terribly steep. The loops take you through varied terrain, from double track trails in fields to single track in wooded areas. There is a mix of packed dirt, smaller rocks, larger rocks, slick rock, and some roots. There are also two river crossings per race loop. This course really has a little of everything, which includes its views. There are amazing overlooks on this course where you can see for miles.

(Details on how the venue change in 2016 came about are here... The first two years the race took place at the highest point in the city of Dallas, Prayer Mountain, which is home to the Mountain Creek Church. The church owns the Big Cedar Wilderness Trail, which is maintained by the Dallas Off-Road Bike Association.)

Course Layout

The course is a one-way traffic 16.67-mile loop.

100 Mile: 6x 16.67-mile loops.

100K: 4x 16.67-mile loops.

50K: 2x 16.67-mile loops.

Half Marathon: 1x a shortened 13.1-mile loop.



Ultras - 50K, 100K, 100 Mile Course Map (Half Marathon map further down)

Click on the map to see it bigger as a PDF!


Half Marathon Course Map

Click on the map to see it bigger as a PDF!


5 Mile Course Map

The 5 mile route does not cross the river at any time. They still get to enjoy the well known scenic overlook where you can see down to the river about 4.25 miles in! And then we cut the half marathon course short to route runners back to the finish line.

Click on the map to see it bigger!


For All Courses:

Details on the aid stations this year...

Mileage is not for contestation. You will cover at least the distance you signed up for.



Here is an elevation profile from data available on Google Earth. This shows the profile for ONE 16.67-mile loop. Therefore, we anticipate the 100 miler will be about 9,600 feet of gain/loss. Click on the picture to see a larger version of the profile.

Here is the elevation profile for the half marathon:


We've been really unlucky three years in a row. The first year, 2014, was a mudfest of constant rain. This resulted in a 20% finish rate in the 100 miler, the 50 miler having to be canceled, and an unusually low finish rate for a 50K.

In 2015, 17 hours into the 100 miler, the entire race had to be cancelled. Storms came through Friday into Friday night, and what wasn't forecasted to happen, they just sat on top of us as we approached midnight. This led to significant flash flooding on the course, which has the highest point in Dallas but also has quite a few valleys and hollows. Runners reported chest deep water. We held the race for an hour to see if the storms would move through and when they didn't and we had more reports of bridges being out and snakes moving out on the trails in the higher elevations to escape drowning, we were forced to cancel all the events.

In 2016, it was a wet weekend after the forecast had shown nothing going into it, and it rained basically the whole race. But we still had a bunch of finishers who pushed through to complete!

In having to move our venue in 2016 for reasons out of our control, we have chosen a venue that is able to handle rain better than a lot of area trails. However, there are limits that any trail can handle. Because this is a State Park, the park personnel have the right to cancel the race before or during the event if they believe everyone's safety will be in jeopardy. We appreciate they are watching out for us, we understand the tough decision, and we hope the weather isn't extreme so they don't have to make that tough decision!



This is not an exhaustive list but some hazards to watch out for on the trail:

  • Snakes - we've had a cold snap recently, so we hope they will have headed to hibernate. There are copperheads spotted in the spring, summer, and fall.
  • Bobcats and coyotes - we don't expect them to give anyone any trouble, but they do live in these woods.
  • Cactus - Be careful going off trail to use the bathroom.
  • River crossings - there are two per race loop, as well as 750 feet along and through a creek that empties into the river. We think it makes this course even more unique and cool. You will get your feet wet in both crossings. In rainy conditions, it may be calf deep. You need to pick your footing carefully on the rock shelves and rocky river floor. Take caution, especially in the middle of the night.
  • Slickrock - it's fine unless it rains and then it lives up to its name. Watch your footing.
  • Loose rocky terrain



As a state park, they have established a grid of trails through their land. It is each participant's responsibility to watch carefully for course markings. We will be using a combination of

  • bright pink contractor tape flagging, with reflective tape on the ends to capture the light of your headlamp in the dark, that will be clothespinned to tree branches and bushes.
  • bright pink stake flags for major field sections that don't have bushes to attach ribbons to
  • arrow signs (left, right, straight)

In spots where there's an intersection, just follow the flagging for the correct route to take if there are no arrow signs specifically. Flagging will be visible from where you are standing in the intersection.

Confidence flagging: For trail sections where there's no possible logical offshoot of a trail that you could take other than the one you are on, you may go as far as a half mile without flagging.

If you ever get to a spot where you are completely unsure of where you are, backtrack on the path you took until you get to course markers. If you become utterly and completely lost, never ever go off trail. Sit down where you are and wait until someone gets to you.

Ultimately, you are responsible for knowing the course.



See here on the Race Details page...



See here on the Race Details page...



All items on this page subject to potential significant change.


Big Cedar Endurance Run © 2014
All Rights Reserved.