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Seth's Fat Ass 50K

Springfield, United States • 20 Dec 2025

Seth’s Fat Ass 50K : December 20, 2025

Seth’s Fat Ass 50K is a looped trail/road event held at Forest Park in Springfield, MA on Saturday, December 20, 2025. The full distance is 50K, run as ten repeated loops of the Harrier’s Snow Storm Classic 5K route. Participants may stop after any loop; there are options to complete one, two, three or all ten loops. Participants are allotted seven hours to complete the event.

Course and logistics

  • One 5K loop
  • Two 5K loops
  • Three 5K loops
  • Ten 5K loops (full 50K)

The course follows most of the local "Bright Nights" route. Roads are not closed to traffic, though traffic is expected to be limited. The start area is in the lot near the baseball fields in Forest Park.

Registration fees are listed as $40 with a higher late fee ($45) plus online entry fees. Race day registration is available for $45 by cash or card. Online registration is handled through Ultrasignup. Parking is available in the lot near the baseball fields and on North Greeting Road; an alternate parking area at 245 Park Drive in Longmeadow is noted as being more than a half mile from the start. Parking inside Forest Park may require a small parking fee. Participants receive event schwag; t-shirts are planned. Visit the organization's website for the most recent information.

United States Massachusetts Springfield

Race information

Website Registration
50 km
50k
Visit the organization's website for the most recent information.
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