Free. You can start with nothing.
A Western States 100 qualifying 100K, paired with a 50K and the women's Trail Sisters Half Marathon, on singletrack above Lake Sonoma in Sonoma County wine country. The 100K climbs Pritchett Peak for a sunrise summit, drops to the Lake Sonoma Visitor Center, then runs an out-and-back on the original Lake Sonoma 50 Mile course to a turnaround at Lone Rock.
Founded 2008 as the Lake Sonoma 50 Miler by John Medinger and Lisa Henson. New race directors Gina Lucrezi and Justin Keller (Trail Sisters) took over in 2022. The Trail Sisters Half Marathon was added in 2023, alongside a move of the start/finish to the Lake Sonoma Visitor Center and a cash purse for the 50 Mile. Through 2025 the spring event was still 50 Mile + Marathon + Trail Sisters Half. For the 2026 edition, a separate fall race then called the California Fall Classic 100K (also a WSER qualifier) moved to April and was rebranded the TERREX Lake Sonoma 100K; a new 50K was added; the 50 Mile and Marathon distances were dropped from the spring lineup and moved to become the 'OG LS50' inside a new October race, the Sonoma Fall Classic, run by Aravaipa Running with founder Tropical John Medinger..
| Mile | Station | Cutoff | Crew access | Bag | Pacer | Med | To next |
|---|---|---|---|---|---|---|---|
| 0.00 | Start | ? | ? | ? | ? | ? | 5.80 |
| 5.80 | Pritchett Peak | ? | ? | ? | ? | ? | 5.60 |
| 11.40 | Woodridge | ? | ? | ● | ? | ? | 1.30 |
| 12.70 | South Lake | ? | ● | ? | ? | ? | 4.60 |
| 17.30 | Island View | ? | ? | ? | ? | ? | 6.90 |
| 24.20 | Warm Springs | 12:30pm | ● | ● | ? | ? | 5.40 |
| 29.60 | Wulfow | ? | ? | ? | ? | ? | 2.70 |
| 32.30 | Liberty Glen | ? | ● | ● | ? | ? | 4.30 |
| 36.60 | Lone Rock | 4:15pm | ? | ? | ? | ? | 4.30 |
| 40.90 | Liberty Glen | ? | ● | ● | ? | ? | 2.70 |
| 43.60 | Wulfow | ? | ? | ? | ? | ? | 5.40 |
| 49.00 | Warm Springs | 8:00pm | ● | ● | ? | ? | 6.90 |
| 55.90 | Island View | 10:00pm | ? | ? | ? | ? | 4.60 |
| 60.50 | South Lake | ? | ○ | ? | ? | ? | 1.60 |
| 62.10 | Finish | 12:00am | ? | ? | ? | ? | ? |
Parking. Park in an organized fashion and follow the water station volunteers. Crews may line up along the southwest corner of the lot.
Return to Stewart Point-Skaggs Springs Road and head up the hill approx.1.75 miles. Turn/continue left on Skaggs Spring road. Follow it for 11.5 miles to the intersection of Old Skaggs Springs Road. Turn right on Old Skaggs Springs Road and follow it for 3 miles to the gate. Park here and walk a half-mile further down the road to the aid station.
Parking. Park at the gate on Old Skaggs Springs Road and walk a half-mile down the road to the aid station. There is no cell phone service at Warm Springs.
runlakesonoma.comReturn up Old Skaggs Springs Road for 3 miles to the stop sign. Turn left onto Stewart Point-Skaggs Springs Road and follow it for 11.5 miles to the stop sign at Rockpile Road. Turn left and follow Rockpile Road for 3.2 miles to the Liberty Glen Campground Road. Turn left and follow this for 0.5 miles. After the entrance station, turn left and follow the road to the Group Campground E.
Parking. The Liberty Glen aid and crew area is at Group Lot E, within the camping area. Crews can see their runner both outbound and inbound here.
runlakesonoma.com2 people have been out there with a camera or a microphone.
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.
Nobody sees it until we have read it. No account, no sign-in.
This changes nothing on the page on its own. Somebody checks it against the race first.
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.
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.
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.
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.
