Grindstone Trail Running Festival, live.

A hundred miles that start at six in the evening

Grindstone starts and finishes at the limestone towers of Natural Chimneys Park in Virginia, in national forest just west of the Shenandoah Valley.

The organiser calls it a highly technical course of high ridges, peaks and valleys in the George Washington and Jefferson National Forest. The 100M (167.4 km, 6,400 m of ascent, about 21,000 ft) starts at 18:00 on Friday with a 36-hour limit. On Saturday the 100K (100 km, 3,350 m, 18 hours) goes at 06:00, the 50K (50 km, 1,550 m, 9 hours) at 07:00 and the 21K (21 km, 500 m, 6 hours) at 08:00. In 2026 the festival ran 17-20 September. The organiser has announced 24 and 25 September 2027 for the next race days.

Every course begins on the ridge of Narrow Back Mountain. The long ones then climb Wolf Ridge and reach the Wild Oak National Recreation Trail. The 100M goes over Reddish Knob, Little Bald Knob, Grindstone Mountain, Lookout and Hankey Mountains, then south over Crawford Knob to Elliott’s Knob, the highest point of the course, before turning home. Each finishes in front of the chimneys. The organiser lists Grindstone as a qualifier for both the UTMB World Series Finals and the Western States Endurance Run, and 100M entrants owe at least eight hours of trail work in the race year.

An 18:00 start means the 100M runs its first night in the mountains, and long stretches of the course are on forest trail between the aid stations. A runner can share a link to their own Livebib broadcast. Family open it in a browser, no app and no account, and see the runner’s position on the course line, the distance covered and a finish estimate that updates as the race goes. When the phone loses signal under the trees or in a hollow, the position is carried forward along the course and marked estimated instead of freezing. The runner decides who gets the link.