Pi Day River Rotation

Pi Day River Rotation - March 14, 2026, Lawrence, KS

The event offers multiple trail race options on the Lawrence River Trails in Lawrence, KS. Distances include:

• Pi Miler - 3.14 miles
• River Rotation Half Marathon - three loops on the River Trails
• 16.24 Miler (Pi Slam) - combines the Pi Miler and the Half Marathon

Races start at the Levee gate, pass through the parking lot, and enter the River Trails on the south side. The trails are described as relatively flat singletrack with a few short hills, flowy and not highly technical, with few roots or rocks. The Half Marathon uses three loops: one counterclockwise loop just under 5 miles, one clockwise loop just under 5 miles, and a 4 Corners Loop just over 3 miles. The Pi Miler follows the 5K Loop route.

Aid stations on course will supply water, electrolytes, energy snacks, fruit, and other items. A smaller aid station is near the 5K turnaround and is encountered about halfway through the Pi Miler. Half marathoners will pass that smaller station on each loop and will also have access to a larger aid station at the trailhead twice during the race. Participants are encouraged to bring reusable hydration bottles or cups; a limited number of cups will be available.

Awards are given for 1st to 3rd place in each gender for the Pi Miler and Half Marathon. Pi Slam finishers receive special swag and are eligible for place awards.

Entries, cutoffs and policies

Registration closes on Tue, Mar 10 at 11:59 PM CT. The event has an end time of 1:00 PM; half marathoners have 4.5 hours to finish and must leave the aid station to begin their final loop by 11:45 AM or continue without race support. Runners may change distance or defer entries by specified deadlines; bib transfers and refunds for cancellations are not allowed. If trails are unsafe or vulnerable to damage, an alternate course on the packed-gravel Lawrence Levee Trail will be used. Visit the organization's website for the most recent information.