
Castro Valley, United States of America · Friday 26 June 2026
We cannot promise you ll encounter any cryptic, aquatic creatures at Loch Chabot, but you might! We DO promise a gorgeous trail run on the scenic trails of Loch Chabot Regional Park, some quality nature therapy, and some incredible views! We ll also hook you up with some awesome swag (an awesome shirt , a handcrafted race woodallion ), a Rock the Loch beer sampler stein , & more), quality post run beverages/snacks, DJ Cryptid spinning your favorite tunes before/during/after the race, and more! If you can t join us LIVE at Loch Chabot, no problem! We re supporting a VIRTUAL participation option as well. Where : Lake Chabot in Castro Valley, CA. When: Sun, 6/28- Early Half Start- 8:15AM (for those needing 3.5-4 hours), Standard Half Start- 9:15AM (for those needing 3 hours or less), 10K Start- 9:30AM, 5K Start- 9:45AM. Course Maps: 5K Course Map , 10K Course Map , Half Marathon Course Map. Course Details: The 5K is 100% paved. It s a great course for conquering your first and/or fastest 5K! The 10K is 50% paved, 50% trail, and includes 1 tough climb. The 10K is a great option for those new to trails. The Half Marathon includes 3ish miles paved and the rest is trail. The Half includes nearly 1,700 feet of ascent/descent. The half is a STOUT challenge we d recommend only for experienced trail runners. Aid Stations: The 10K includes 1 aid station approximately 3 miles into the race. The Half Marathon includes aid stations at 4.1 miles, 7.65 miles, and 9.85 miles. Aid stations include water, Skratch Labs electrolyte drink, GU Energy products, Saltstick products, chips, and pretzels. The Experience: All Rock the Loch participants receive.... An epic, trail run at Loch Chabot (assuming you re not participating virtually) An AWESOME race woodallion designed by Aravaipa Artworx A sweet lifestyle tee A custom Rock the Loch beer sampler stein . Post race snacks/beverages including Bellwether Farms yogurt, Jambars, and more! Access to the post race BREWFEST DJ Cryptid spinning y
Adjusted Time
1:40:47
Time difference: -4.2 minutes compared to a flat, road, temperate course.
The Rock the Loch 5K/10K/Half Marathon (LIVE or Virtual) is a half marathon held in Castro Valley, United States of America, scheduled for Friday 26 June 2026. The course is run on road surface with 0m of total elevation gain, reaching a maximum altitude of 0m above sea level. For registration and full race details, visit the official The Rock the Loch 5K/10K/Half Marathon (LIVE or Virtual) website.
This is a very flat course with only 0m of total elevation gain across the full distance. The course ranges from 0m to 0m above sea level — a 0m elevation range that makes it one of the flatter races available. Runners targeting a personal best will appreciate the minimal climbing.
The Rock the Loch 5K/10K/Half Marathon (LIVE or Virtual) is run on road surfaces, which provide the fastest and most predictable conditions for marathon running. Road courses allow for consistent pacing and are typically the best choice for runners targeting a personal best time.
Our difficulty rating for The Rock the Loch 5K/10K/Half Marathon (LIVE or Virtual) is calculated using a model that combines elevation gain, temperature impact, and surface type. Use the difficulty calculator above to enter your target finish time and see exactly how many minutes this course would add or subtract compared to a perfectly flat, cool, road-based half marathon. Faster runners and slower runners are affected differently by the same course conditions, so the difficulty is personalised to your pace.
Looking for an easier marathon or a tougher challenge? You can also compare The Rock the Loch 5K/10K/Half Marathon (LIVE or Virtual) against other half marathons to find the right race for your goals.
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