This is a simplified binomial estimate, not an official figure. Real odds depend on date choice, group size, cancellations and daily demand. Verified 2026-10-01 against recreation.gov and NPS/BLM pages; all reference odds marked "est." are third-party estimates. 本工具为简化二项概率估算，非官方数据。真实中签率还取决于日期选择、团队人数、取消名额与每日热度。参考数据核实于 2026-10-01，来源 recreation.gov 与 NPS/BLM；标 "est." 均为第三方估算。 recreation.gov · nps.gov