Saturday, May 13th, 2023

Registration Coming Soon

Kick off spring with an annual Mermaid classic that features a 5k, 10k, Half Marathon, the Sirena18 mile, the Sirena 18 mile (Relay), or Virtual run or walk. The course is virtually flat as it follows a mix of dirt and paved trails. Enjoy the fresh air and positive vibes. Mermaids receive a stylish race shirt, finisher medal, necklace and post race food.

Walkers and runners of all ages and abilities are celebrated at Mermaid events. To remain within our permit, the Sirena18 mile distance participants this year will need to maintain at least a 14 min mile in order to finish in 4hr 12 min. We will have a 7:00am early start option available for anyone needing additional time. There are no time limits for the other distances.


Sirena18 - 7:30 a.m.
Half - 8:00 a.m.
10K - 8:30 a.m. 
5K - 9:00 a.m.
mermaid dash (ages 9-12) - 10:00 a.m.
mermaid dash (ages 6-8) - 10:05 a.m.


Race Updates are sent the week of the event.

The Mermaid Dash is a 1.5 mile dash for girls & boys ages 6 to 12.

Dashers receive a medal, necklace and post race food. Parents are

encouraged to let Mermaid Dashers run on their own. The Dash is

$15.00 online and $20.00 race day. Entry fee does not include a

race shirt



5K [map]

10K [map]
Half Marathon [
Sirena18 (3 loops around Quarry Lakes) [
map coming soon]


Before - 3/1/22
5K: $49
10K: $59
half marathon: $69
Sirena18: $79

Sirena18 2 Person RELAY:  $99 per team

Virtual: $49

4/1 - 4/27

5K: $59

10K: $69
half marathon: $79
Sirena18: $89

Sirena 18 2 person relay:  $109 per team
Virtual: $59

Packet Pickup & Race Day* (4/28 to 4/30)

*If race sells out there will be NO race day registration


5K: $64

10K: $74

half marathon: $84

Sirena18: $94

Sirena18 2 Person RELAY: $114
Virtual: $64 


24 & Under

Receive a 20% discount off the current price

70 & Over

5K, 10K, Half, Sirena: Free (in-person only)

3/1 - 3/31
5K: $54
10K: $64
half marathon: $74
Sirena18: $84

Sirena18 2 Person RELAY:  $104 per team

Virtual: $54


We are happy to issue you a credit toward a future Mermaid Series event. To receive a credit, please email us at a minimum of 10 days before the event date. We will email you back a confirmation along with the amount of your future race credit. Please keep the confirmation email for your records.


Our event credit and event cancellation policy is outlined on the event "Participant Waiver" which is agreed upon when you registered:

Mermaid Series (pdf) Wavier


The following credits will be issued: 

• Run - Entry fee minus $10 processing fee.
• Duathlon - Entry fee minus $10 processing fee
• Triathlons - Entry fee minus $10 processing fee


Where: TBD
When: TBD
Directions: Google Maps 

**Athletes must bring a photo ID in order to pick up their packet

Where: Quarry Lakes Regional Park
When: 12:00 p.m. - 6:00 p.m.
Google Maps
** Athletes must bring a photo ID in order to pick up their packet

SATURDAY (race morning) Packet Pickup
Where: Quarry Lakes Regional Park
When: 6:00 a.m. - 9:00 a.m.

Directions: Google Maps
Athletes must bring a photo ID in order to pick up their packet

**We recommend you arrive a minimum of one hour before your race 


We suggest to arrive a minimum of 1 hour prior to your race. For specific directions please reference the Google Map for Quarry Lakes Regional Park, Fremont, CA


Packet pickup - Registration 

What do I need to bring to packet pick-up/registration?
Bring your PHOTO IDENTIFICATION (ID) or a copy of your ID in order to receive your packet. A valid driver’s license or a valid passport is best. Minors are not required to show a photo ID. 


Can I pick up my friend’s packet for them?
Yes! Bring a copy of their photo ID and we’ll give you their packet.  You may have a photo of your friend's photo ID on your phone.


Are we required to pick up our packets before race day?
No, but we strongly recommend that you do. This allows you to get ready for your race instead of waiting in a line on race day.

What time should we be there on race day?
Check-in opens at 6:00 a.m. We recommend you get there 60 minutes before your start time to park and get ready for the race. If you didn’t get your packet before race day, you may want to give yourself even more time.

How soon does one need to register for the event?
The earlier, the better. Mermaid events have sold out in the past. To guarantee your entry we recommend you sign up early. Plus, the prices increase as the event date gets closer.

If the event closes, will there be a waiting list?



If I cannot race, can I give someone else my race number?

No. Race entries are non-transferable.  


How do I know you received my entry?

You should have received an email confirmation from the registration system. If you can’t find it, you can email us at We will verify your participation from our registration list.

Can I get a refund?

Unfortunately, there are no refunds. However, we do have an awesome cancelation policy. Email us at at least 10 days prior to the event and we’ll give you a credit toward a future race. The credit amount is your entry fee minus a $10 processing fee.

Run Course


How many miles is 5K? 10K? Half Marathon?
The 5K is 3.1 miles, the 10K is 6.2 miles, and the Half Marathon is 13.1 miles.  

What is the Sirena 18 mile 2 person relay?

The Sirena 18 mile 2 person relay is our newest sub-event.  We give the option for teams of two to run the Sirena 18 mile course by

splitting up the distance into two parts. The first leg is 7.5 miles and the second leg is 10.5 miles.  Both team members must be registered for the Sirena18 Relay.


Will you provide a shuttle to/from the transition point for Relay teammates?

We will provide a shuttle to/from the relay exchange point.  The team member who runs the second leg will be shuttled out to the exchange point. The first team member will start with the Sirena 18 mile runners and will be shuttled back to the start line after they meet up with their team member at the exchange area.

I want to run back with my teammate who is running the second leg of the relay.  May I do so and not get on the shuttle?

Yes, you may run back with your teammate to the finish line. You will need to let the volunteer at the exchange tent know so that

we can mark off as not needing the shuttle back to the start line.

Is the course hilly?

The course is virtually flat, but most of the course is a dirt path, some of which is uneven and narrow. 

Is there is a time limit?

We do have a time limit for the Sirena18 Mile. Participants must maintain a 14min pace and complete the 18 miles in 4 hours and 12 minutes. For those needing additional time we will have offer a 7:00am early start. All other distances DO NOT have a time limit. 

Do you have aid stations? What kind of hydration/food is on the race course?

Yes, we have plenty of aid stations. Water, Ultima Replenisher electrolyte drink, and Luna bars are available at aid stations along the course.    


Can I run with a baby stroller?

Yes, you can run with a baby stroller, but the course is on a mostly dirt path, so the ride will be bumpy. If you choose to use a baby stroller, please start towards the back of the pack at the start line. 

Do you have prizes for winners?
Yes! We will have an awards ceremony at the expo. Awards are given to the 1st, 2nd, and 3rd place overall female winners for each distance and 1st, 2nd, and 3rd place female winners of each age group. You must be present at the awards ceremony to pick up your award.  Awards will not be mailed out. We do not offer awards for male categories.

What are the Age Groups?

Mermaid Age Groups are currently 10 and under, 11-14 15-17, 18-19, 20-24, 25-29, etc. Age groups from age 20 and over are separated by 5 year increments.  


I belong to a club or organization. Do you offer group discounts?
Yes! Have your club president or representative email us at to get the discount code.

How many do I need in my group to be eligible for a group discount code?
6 or more.



Are men allowed to compete in a Mermaid event?
Yes! Men can register and participate. However, since Mermaid is primarily a women’s event (about 97-98% of participants are women), men are not eligible for awards.

Do I have to wear my paper, race number?

Yes, you are required to run with your bib number. The bib is used for timing, identification, and race photos. 

I heard this event uses Chip Timing. What is Chip Timing?
Chip timing allows us to record your time using a computer and gives the most accurate results. Your timing chip is attached to your bib.


Photos will be available approximately one to two weeks following the event.

2022 photos

2019 photos

2018 photos

2017 photos

2016 photos

2015 photos

2014 photos

2013 photos

2012 photos

Event photography by: Facchino Photography specializes in off-road event photography. Capturing athletes in their moment and allowing them flexibility in viewing and ordering convenience.