If you were going to pick one element of the Equinox Marathon that embodies the race, it would be Ester Dome. "The Dome" is the pinnacle of the race, topographically and figuratively.
The ascent of Ester Dome begins "officially" at the 9-mile mark on the course. Runners reach the first summit (Ullrhavn Summit) 3.4 miles/5.4Km and about 1500 vertical feet/450 vertical meters later. Needless to say, it is important to adjust ones pace when ascending.
Once runners reach Ullrhavn Summit, the 4.7 mile long Out-And-Back begins - see the FAQ about the Out-And-Back. This hilly section often decides the race.
The descent from Ester Dome is as crucial as the ascent. The descent starts at the 17.1 mile mark with the semi-suicidal plummet down the "Chute," which drops several hundred feet in about 1/3 of a mile of rutted, loose gravel with very bad footing. After that, the course makes a 90-degree lefthand turn and gets on a trail which continues to descend, albeit more gradually than the chute.
The trail ends past the 19-mile mark, at which point the course continues to descend on Henderson Road, which starts out as a well-graded gravel road, then becomes a paved road about 1/2 mile later, just past the 20-mile mark. From that point, it's another 1.5 miles of steady, rolling downhill to Gold Hill Road, where you can breathe a sigh of relief, knowing that you have put "the Dome" behind you.