Western States
Type the course. Do not trust a generic 100.
Western States is 100 miles from Olympic Valley to Auburn, with roughly 18,000 feet of climbing and a 30 hour cutoff. Those are the numbers to put in the form: distance 100 mile, elevation gain 18000, terrain technical, night running yes. The plan does not download the official course.
What the buffer is doing
The calculator splits 100 miles and the gain you entered into eight sections. A runner at about 40 miles a week is given a 12 minute flat pace, then 18 minutes per 1,000 feet because the trail is technical. Later sections are slower than the first. The buffer is 30 hours minus that total. It is a planning clock, not a qualifier prediction.
The weeks around it
You need at least 16 weeks. Back-to-back long runs belong in the build if your weekends allow them. One run a week in that block is at night. The taper is three weeks. Fueling for the long runs is at fuel.lsbapps.com, and the drop bag sits next to the list at pack.lsbapps.com.
Build a Western States previewA shorter race is the 50K plan
UltraPlan is a general trail schedule, not medical advice and not a substitute for a coach or a physician. Stop for chest pain, dizziness, or pain that changes your stride. Cutoffs, aid, and crew notes are planning numbers, not a promise the race will hold that clock.