Lake Sonoma 100K, 50K, TS Half Marathon
- Date Sat 11th April 2026
- Time 5:00AM PDT
- Location Geyserville, California
- Price $117.60 - $295.00
- Races 3 races
- Distances Half Marathon, Ultra
Event summary
Get ready for an unforgettable trail running experience at the Lake Sonoma 100K, 50K, and Trail Sisters Half Marathon on April 11th, 2026, in the stunning Geyserville, Sonoma region of California! This exciting event, presented by adidas TERREX, promises an exhilarating day filled with breathtaking scenery and challenging courses.
The 100K race kicks off with a thrilling climb up Pritchett Peak, leading participants through beautiful landscapes and offering a unique out-and-back segment along the original Lake Sonoma course. Meanwhile, the 50K offers a fantastic mix of rolling single track trails and scenic views, ensuring an adrenaline-pumping experience as runners cross the picturesque lake bridge and tackle a final downhill stretch to the finish line. For a more relaxed challenge, the women's-only Trail Sisters Half Marathon will inspire camaraderie among participants as they navigate steep ascents and enjoy the support of fellow runners.
Join us in celebrating the spirit of community and achievement at this remarkable event, culminating in a festive Celebration and Thank You gathering at Coyote Sonoma. Share stories, enjoy delicious food and wine, and connect with fellow trail enthusiasts. Don't miss out on this incredible opportunity to embrace the great outdoors and make lasting memories!
The 100K race kicks off with a thrilling climb up Pritchett Peak, leading participants through beautiful landscapes and offering a unique out-and-back segment along the original Lake Sonoma course. Meanwhile, the 50K offers a fantastic mix of rolling single track trails and scenic views, ensuring an adrenaline-pumping experience as runners cross the picturesque lake bridge and tackle a final downhill stretch to the finish line. For a more relaxed challenge, the women's-only Trail Sisters Half Marathon will inspire camaraderie among participants as they navigate steep ascents and enjoy the support of fellow runners.
Join us in celebrating the spirit of community and achievement at this remarkable event, culminating in a festive Celebration and Thank You gathering at Coyote Sonoma. Share stories, enjoy delicious food and wine, and connect with fellow trail enthusiasts. Don't miss out on this incredible opportunity to embrace the great outdoors and make lasting memories!
Organiser's Description
Join us in Healdsburg, California, on April 11th 2026 for the TERREX Lake Sonoma 100K, 50K, and Trail Sisters Half Marathon! We are excited to have adidas TERREX back as our presenting partner!
We are stoked to team up with Mountain Outpost to bring you full livestream coverage, athlete panels, interviews, and commentary from special guests!
LAKE SONOMA 100K
The 100K course will start with a climb up Pritchett Peak with a water only stop at the top. Once you reach the summit youll head back down toward the Lake Sonoma Visitors Center and then up to the hill to South Lake Trailhead where youll embark on an out and back of the original old school LS course and then back down the hill to the finish. Its the same great Lake Sonoma Relentless experience, only this time with a big climb to kick it all off!
LAKE SONOMA 50K
Its not worth it unless you have to work for it! The 50k start is located in the green space next to the Lake Sonoma Visitor Center (you cant miss it). After a short road section to get the field spread out the course then continues onto beautiful rolling single track trails. You will continue past South Lake, Island View, Warm Springs Creek, Wulfow, Liberty Glen and the Bummer aid stations, finally crossing the scenic lake bridge. Remember to save some juice for the last few miles, as you have a screaming downhill towards the finish. The race starts at 7:30am.
Dont forget to enjoy the views! and be sure to take a dip in the water to cool off. (but dont drink!)
TRAIL SISTERS WOMEN'S HALF MARATHON
The Trail Sisters (TS) Half Marathon is a womens only event. It was created to foster encouragement and camaraderie amongst all abilities and experience levels. This out and back course starts with steep trail ascent to South Lake Trailhead, but also provides a speedy descent to the finish. True to its label, you can expect relentless rolling hills that will challenge your mind and body. Lucky for you though, you will share the journey with a community of supportive Trail Sisters to help you through! You will have 4 and half hours to complete the half marathon course.
COME CELEBRATE!
Lake Sonoma isnt just a race event, its a celebration. We always complete the weekend with a Celebration and Thank You event at Coyote Sonoma in Healdsburg, CA. Everyone involved with the event is invited to enjoy wine, charcuterie, and share stories from the weekend.
See you on that start line!
Gina & Justin
LS Race Directors
We are stoked to team up with Mountain Outpost to bring you full livestream coverage, athlete panels, interviews, and commentary from special guests!
LAKE SONOMA 100K
The 100K course will start with a climb up Pritchett Peak with a water only stop at the top. Once you reach the summit youll head back down toward the Lake Sonoma Visitors Center and then up to the hill to South Lake Trailhead where youll embark on an out and back of the original old school LS course and then back down the hill to the finish. Its the same great Lake Sonoma Relentless experience, only this time with a big climb to kick it all off!
LAKE SONOMA 50K
Its not worth it unless you have to work for it! The 50k start is located in the green space next to the Lake Sonoma Visitor Center (you cant miss it). After a short road section to get the field spread out the course then continues onto beautiful rolling single track trails. You will continue past South Lake, Island View, Warm Springs Creek, Wulfow, Liberty Glen and the Bummer aid stations, finally crossing the scenic lake bridge. Remember to save some juice for the last few miles, as you have a screaming downhill towards the finish. The race starts at 7:30am.
Dont forget to enjoy the views! and be sure to take a dip in the water to cool off. (but dont drink!)
TRAIL SISTERS WOMEN'S HALF MARATHON
The Trail Sisters (TS) Half Marathon is a womens only event. It was created to foster encouragement and camaraderie amongst all abilities and experience levels. This out and back course starts with steep trail ascent to South Lake Trailhead, but also provides a speedy descent to the finish. True to its label, you can expect relentless rolling hills that will challenge your mind and body. Lucky for you though, you will share the journey with a community of supportive Trail Sisters to help you through! You will have 4 and half hours to complete the half marathon course.
COME CELEBRATE!
Lake Sonoma isnt just a race event, its a celebration. We always complete the weekend with a Celebration and Thank You event at Coyote Sonoma in Healdsburg, CA. Everyone involved with the event is invited to enjoy wine, charcuterie, and share stories from the weekend.
See you on that start line!
Gina & Justin
LS Race Directors
Races
-
Trail Sisters Women's Half Marathon
Incl. $7.60 Fee
Sat 11th April 2026 (9:30AM PDT)
$117.60
OPENS 01 OCTThe Trail Sisters (TS) Half Marathon is a womens only event. It was created to foster encouragement and camaraderie amongst all abilities and experience levels. This out and back course starts with steep trail ascent to South Lake Trailhead, but also provides a speedy descent to the finish. True to its label, you can expect relentless rolling hills that will challenge your mind and body. Lucky for you though, you will share the journey with a community of supportive Trail Sisters to help you through! You will have 4 and half hours to complete the half marathon course. -
Lake Sonoma 100K
Incl. $15.00 Fee
Sat 11th April 2026 (5:00AM PDT)
$295.00
OPENS 01 OCT -
Lake Sonoma 50K
Incl. $12.10 Fee
Sat 11th April 2026 (7:30AM PDT)
$197.10
OPENS 01 OCT
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3227 Stewarts Point-Skaggs Springs Rd, Geyserville, 95441, CA, United States
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Lake Sonoma 100K, 50K, TS Half Marathon
