March 9 - 14, 2026
Viper 300
Cordova, TN • 300 Miler, 200 Miler, 100 Miler, 53K, 25K
Registration closes: Sat, Mar 7 @ 11:59PM CT
About the Race
Welcome to the ultimate test of endurance. This isn't your average Sunday morning jog in the park. We're talking about a grueling 300, 200, and 100-mile race that will push you to your limits and beyond. But don't let that scare you off, because trust us when we say, there's nothing quite like conquering this challenge.
As you make your way through the picturesque Shelby Farms, surrounded by breathtaking landscapes and wildlife, you'll find yourself questioning why you ever doubted yourself in the first place. The sense of accomplishment as you cross that finish line will be unlike anything else you've ever experienced.
But let's not sugarcoat things here - this race is no walk in the park (pun)
Picture this: a trail that takes you on an adventure through a unique blend of terrains. It's a wild mix of paved paths and thrilling single-track trails that wind their way through serene lakes and lush wooded landscapes. But hold on, it doesn't stop there! As you traverse this extraordinary path, keep your eyes peeled for some unexpected company. Yes, we're talking about the local wildlife – deer and even mighty buffalo sharing the trail with you! So gear up, embrace the untamed, and get ready to experience nature like never before. It's time to hit the trail and embark on an unforgettable journey filled with breathtaking views and encounters with the wild side. Let's go! 🌿🦌🦬
Our 33ish mile loop is a course designed to test your limits and ignite your inner competitor. Looking for something a little less intense or uniquely tailored to your goals? We also offer a 53k Friday the 13th night race distance for those ready to up their boundaries and a 25k option for runners seeking a challenging yet achievable feat.
Each distance represents an opportunity to grow, conquer, and redefine what you're capable of. Whether you're chasing a personal record or simply looking to push beyond your comfort zone, we've got the perfect course for your next adventure. Are you ready to take the leap?
Dates and Times
300 miler - Monday, March 9th at 7am - 137 hr. time limit
200 miler - Wednesday, March 11th at 7am - 89 hr. time limit
100 miler - Friday, March 13th at 7am - 41 hr. time limit
53k - Friday, March 13th at 5pm - 31 hr. time limit (Night race)
25k - Saturday, March 14th at 8am - 16 hr. time limit
Locations and Parking
Start / Finish & Key Locations
Hyde Lake Pavilion (Start/Finish Line) crewed and sleep station
Shelby Farms Park
6903 Great View Dr. N.
Memphis, TN 38134
Tour de Wolf Pavilion Aid Station (TDW Aid Station) crewed and sleep station
Shelby Farms Park
6903 Great View Dr. N.
Memphis, TN 38134
Wolf River Refuge Trailhead - (Refuge) - crewed during daylight hours M-TH. Crewed Aid Station Friday - Friday night - and all day Saturday.
Unmanned Water Stop & Aid Station
S. Walnut Bend Rd.
Memphis, TN 38018
After-Dark Park Entry
Use Gate 10
Mullins Station Rd. & Pine Lake Dr.
(Look for the large orange/green Shelby Farms Park sign)
Directions from Gate 10: Enter through Gate 10.
Follow Pine Lake Dr. to the stop sign.
Turn left at the stop sign.
Immediately turn right into the gravel parking / field lot.
This is the race parking area.
Runner Parking (Overnight & Crew Access)
If you are running the race and leaving your vehicle overnight:
Park in the gravel / field lot next to the TDW Aid Station
(near bathrooms & playground)
Do NOT park in the paved lot next to the bathrooms.
White race signs will guide you.
You will pass your vehicle twice each loop, allowing you to:
Use it as a personal aid station
Change gear
Rest or sleep if needed
Access this lot via Gate 10
Drive straight to the stop sign
Parking area will be in front of you and to the left
Packet Pickup
Packet Pickup will be on Sunday, March 8th from 1-5pm at the Hyde Lake Pavilion Aid Station inside Shelby Farms Park. It is recommended if you are running the 300 miler to pick up your packet during this time. All other race distances are welcome to pick up your packet at this time too.
Packet pickup will open back up at 8am on Monday, March 9th and remain open until your race time. You may pick up your packet anytime during the daylight hours before your race while the Park is open.
Aid Station Information
Aid Station, Crew, & Drop Bag Overview – 33.4-Mile Loop
Refuge Unmanned Water Station — Mile 10.8 (crew only during daylight hours) no drop bags
TDW Aid Station — Mile 20.8 (crewed and drop bags) sleep station with cots, pillow, and blanket.
TDW Aid Station — Mile 27.0 (crewed and drop bags) sleep station with cots, pillow, and blanket
Hyde Lake Aid Station — Mile 33.4 (Loop Completion - crew and drop bags) sleep station with cots, pillow, and blanket.
Aid Station Setup
Before Friday at 7:00 AM
The 33.4-mile loop will include:
2 fully manned Aid Stations, but you will hit the TDW Aid Station twice in a loop
1 unmanned water station (Refuge – Mile 10.8)
This setup applies to 300-mile and 200-mile runners until Friday morning at 7am
Beginning Friday at 7:00 AM
The loop will include:
3 fully manned Aid Stations
300M & 200M runners will have all Aid Stations fully manned including the Refuge Aid Station.
100M & 53K runners will have 3 fully manned Aid Stations each loop.
Crew Access
100-Mile & 53K Runners
All fully manned Aid Stations allow crew access.
300-Mile & 200-Mile Runners
Refuge Trailhead (Mile 10.8) is crew accessible from Sunrise - Sunset Monday-Thursday only
24-hour access Friday–Saturday
Once all Aid Stations are fully manned Friday morning, all manned Aid Stations become crew accessible.
Drop Bags
Drop bags are permitted at:
Hyde Lake Aid Station (Mile 33.4 - the start/finish line
TDW Aid Station (Miles 20.8 & 27)
Additional rules:
Additional Notes
A fully manned Aid Station is located at the Start/Finish, accessed after every loop.
25K runners will pass through the TDW Aid Station twice during their race.
We will open up an additional manned Aid Station from 5pm - Midnight on Friday, March 13th at Mile 6 and at Mile 14.5. This is primarily for the 53k runners but any runner on the course at that time can use this manned Aid Station for hydration and nutrition.
Viper Course Loop - 33.4 miles
Route map for Viper 300 Route 2026 by James Boler on plotaroute.com
Viper 25k Course
Route map for Viper 25k by James Boler on plotaroute.com
Live Tracking
300-, 200-, and 100-mile races will be Live Tracked
Race Rules
Race Rules:
Please read carefully. It’s every runner’s responsibility to know all the rules. These are common rules in ultras and not overly restrictive. In our experience the ultra-community is very trustworthy and intentional breaking of rules is almost unheard of. Problems typically only arise when someone doesn’t understand the rules and breaks them unintentionally.
- NO DROPPING DOWN IN RACE DISTANCE DURING THE RACE – As with all of our races, we don’t allow “finishes” in distances other than what was signed up for. If you are signed up for the 100-miler, you must complete 100-miles or you DNF.
- No muling – a runner must carry all their own gear, food, water, everything. Therefore, pacers cannot give a runner any of their water, food, etc. anywhere except full/manned aid stations. At full/manned aid stations pacers and crew may assist their runners however necessary.
- No crewing outside full/manned aid stations – Crew cannot help their runner in any way outside of manned aid stations. DO NOT take anything from or give anything to runners outside of manned aid stations (NO ASSISTANCE).
- Trekking poles are allowed but please be courteous to others if using them.
- If you are planning on using a pacer and/or crew, see the “Aid Station and Pacers” section for a full list of rules.
- Littering of any kind at any aid stations, on the trails, or at the finish line is strictly prohibited.
- You may not cut the course. You must follow and stay on the trail and course and you may not shortcut it in any way. If there is a flag or marker it means stay on the trail the marker is on. It’s your responsibility to know and stay on the course. If you fail to run the course as marked you will not receive an official finish time and will not be eligible for an award – no time adjustments, no exceptions.
- You must complete the course on foot, with no assistance from vehicles, bicycles or animals. No skateboards, scooters, unicycles, hot air balloons, roller skates, sled dogs, or wagons (you get the idea).
- While headphones are allowed, please remove your headphones when approaching an aid station. It’s impolite not to.
- Please be aware of your surroundings when a runner approaches you to pass. Be respectful to other runners and make sure you can hear them when they tell you they are about to pass you.
- You are responsible for the behavior of your crew and your pacer. Out of control behavior from crew or pacer could disqualify you from the race. No one wants that and it won't be tolerated at any Mamba Trail Runners race.
- Being rude, discourteous or otherwise annoying race volunteers or staff is grounds for disqualification. Same with being rude or annoying to other runners or anyone else on the course, such as bicyclists, or hikers.
- If you receive an IV, oxygen or break a leg, your race is over. Let’s keep all our inside parts on the inside, please!
- No stashing food, drink or other supplies along the course. Drop bags at specified aid stations only.
- Generally, no cheating. If you wonder if what you are doing is cheating, it probably is. If you’re really not sure, ask us before you do it.
Refunds and Transfers:
No refunds and no bib transfers will be permitted. Entry can be deferred for 50% race credit if done at least 60 days prior to the race. Entry can be deferred for 25% race credit if done at least 30 days prior to the race. No race credit after March 1st, 2026.
A runner may change distances as long as spots are available in the requested race. Refunds will not be issued if a runner chooses to move to a shorter distance.
Pacers
Pacers:
- Pacers will be permitted for the 300 mile, 200 mile and 100 mile distances. No pacers will be permitted for the 53k or 25k.
- Runners are permitted to have ONE pacer at a time.
- Pacers can be picked up at the Start/Finish Aid Station and the Tour De Wolf Aid Station. Pacers can start pacing the 300 miler after 3 loops (100 miles). Pacers can start pacing the 200 milers and 100 milers after 2 loops (66.8 miles)
- Pacers may NOT carry water, food, flashlights, clothing or other supplies for their runner. Muling is strictly prohibited. Pacers caught muling for their runners will result in a disqualification of the runner.
- Each pacer must pick up their pacer number and sign a release form at Packet Pickup before the race. No pacer can pace without a number and signing the release form.
- Pacers must enter and leave each aid station with their runner and must clearly identify themselves to aid station personnel. Pacers may accept aid at aid stations.
- Pacers must stay with their runner at all times; a pacer may not run ahead of their runner to an aid station. If the runner drops, then the pacer drops with them. The only exception to this rule is in an emergency where the runner cannot physically continue. In this case the pacer may continue to the nearest aid station for assistance. Note that in the event this happens, the runner will be removed from the race for safety reasons. .
- Pacers may carry their own supplies and food.
- If a runner withdraws from the race, the pacer must withdraw as well. No pacer can run without their registered runner.
- The pacer is a companion, not a leader. That is, (and we know this one is hard to enforce, so we hope that you do the honorable thing) the runner is supposed to “lead” and find and follow the course on his/her own. The pacer should always follow the runner.
- While a pacer is allowed, this race can be run without one. Road shoes are perfectly fine for this course, but it would be best to have a set of trail shoes too. Trekking poles are allowed but not required.
Photographer
We have one of the best coming to be the official photographer of the race. Jenny El Tee is bringing her photography talent to get the best shots of all runners and their race experience. Her work has been featured multiple times on the front cover of Ultra Running Magazine (March 2023 and November 2021) and being published numerous times with photos and articles in the magazine, including the Mamba 100 (March 2024 issue). So your photo from the Viper races just might make it in Ultra Running magazine!
Please wear your bib on your front so Jenny knows you are a Viper runner and captures your picture. There are so many visitors in the Park, that if you have your bib on your back, Jenny won't know if you are a runner or a Park visitor.
About our Hosts
At 4,500 acres, Shelby Farms Park is one of the largest urban parks in the country! Located in Memphis, Tennessee, the Park is both a vibrant community hub and a retreat from the hustle and bustle of urban life.
Public parks like Shelby Farms Park play an important role in creating a just and equitable community for all, and everyone is welcome here! Whether you play the Park on foot, on wheels, in the trees, in the open or on the water, Shelby Farms Park has something for everyone.
Shelby Farms Park features more than 40 miles of trails, both paved and unpaved, that are popular for walking, biking, running and hiking. The Park's trail network includes Shelby Farms Greenline, an iconic 10.65-mile paved cycling and pedestrian trail that connects the heart of Memphis to the heart of Cordova through Shelby Farms Park.
The Park is home to more than 20 bodies of water which provide plenty of opportunities for fishing.
It's also home to a herd of buffalo!
Kids can play and discover all sorts of fun at the award-winning Woodland Discovery Playground and make a splash at the Water Play Sprayground.
For more unique adventures, try horseback riding, treetop adventures or play a game of paintball or laser tag.
There is even fun to be had for four-legged friends! Dogs are welcome to explore the Park's trails (on-leash, leash in hand at all times) and to visit The Outback for off-leash fun!
If you work up an appetite, grab a quick snack in the Lake's Edge Shop, or head to the restaurant located in the Park!
Shelby Farms Park is a people-powered park -- Shelby Farms Park Conservancy is proud to raise 75% of the Park's $5+ million annual operating budget! Shelby Farms Park and Greenline are managed and operated by Shelby Farms Park Conservancy, a 501(c)3 nonprofit organization.
For More Information
For more information join these pages:
Facebook Private Group: Mamba Trail Runners (this page is packed with information from group challenges to a runner's bio.)
Instagram: Mamba Trail Runners and Mamba__XT
Youtube: Mamba Trail Runners
Event's current local time: 2:52 PM CT