Haunted Half Marathon and 5K by Run the Undergrad

Haunted Half Marathon and 5K by Run the Undergrad is set for October 24, 2026 at Porter Park in Rexburg, Idaho, with the half marathon (13.1 miles) and the 5K both starting at 10:00 a.m. Both routes follow tree-lined paths and open ground dressed with decorations and staffed by costumed volunteers. The atmosphere is family-friendly during the day and turns darker and more theatrical once the light goes, and runners of every level are encouraged to show up in costume.

A half marathon in late October makes a good end-of-season target: you can build through the summer and close the year with a real distance behind you. Give yourself twelve to sixteen weeks, with one long run each week climbing toward 11 or 12 miles. The 5K is the sensible pick if you would rather race hard for 20 minutes than spend two hours managing an effort.