Brazos Bend 100

The Brazos Bend 100 runs on the first weekend of December in Brazos Bend State Park, south of Houston near Needville, and it is built for speed. The organiser, Trail Racing Over Texas, calls the course 99.9% flat, with one "hill" that rises ten feet over a tenth of a mile; the rest is crushed rock, shaded hiking trail and horse trail, and most runners race it in road shoes. The park is best known for its birds and its American alligators, which line the course and have never caused an incident.

The 100 mile starts at 6:00 a.m. on the Saturday and the 100K at 7:00, and both close at 2:00 p.m. on the Sunday, 32 and 31 hours later. Every lap passes the Elm Lake start and finish, where runners keep their own gear between loops. A 100 mile finish inside the 32 hours qualifies for the Western States lottery, and because the race falls on the same weekend as the draw, runners have been picked for Western States while still out on the course.

A loop of about 16.7 miles through Brazos Bend State Park, started and finished at the Elm Lake Pavilion, with three fully stocked aid stations and several unmanned water stops. The 100K opens with its own first loop before joining the main loop the 100 mile runs, and a few intersections are signed by event. The organiser publishes no elevation figure: it calls the course 99.9% flat, with a single ten-foot rise. There are no drop bags on course; runners set up their own support area on the grass at Elm Lake and use it between laps.

Entry is first-come sign-up on RunSignup, with no lottery and no qualifying standard. The 100 mile is capped at 300 runners and the 100K at 170. Registration for 2026 opened on February 13, and both ultras were still open in October at $274 and $234.20 including fees. Park passes for registered runners are included; pacers register separately, and 100 mile runners may have one for the last two laps.