San Joaquin River Trail 50K

This is the Central Valley's late-season ultra, run on the San Joaquin River Trail when the foothills are cool and green is starting to return. San Joaquin Running has organized the race since the mid-2010s, and the event once carried a 100K as well. The winter date makes it a natural season-capper, and 25K and 10K options let training partners share the same morning.

The race starts and finishes at the South Finegold Picnic Area on Millerton Lake and follows the San Joaquin River Trail into the Sierra foothills. The climbing comes in rolling, punchy grades that add up to roughly 5,500 feet over the 50K, much of it on exposed grassland and oak-studded singletrack above the water. Aid stations sit about every five miles, and 50K runners can pick up a pacer at mile 16.

Early December mornings in the foothills are cold, often in the 30s at the start, with valley fog possible low on the course. Clear days warm into the 50s with real sun exposure on the open grassland sections. Rain is possible this time of year and can turn some stretches slick, so layers that shed easily are a smart choice.