Which zone has max capacity of 23 in a group under 2 at Robbers Roost?
CREATE TABLE "grand_canyon_zoning_and_use_limits" (
  "area" text,
  "name" text,
  "zone" text,
  "group_s" real,
  "parties" real,
  "max_people" real,
  "camp_type" text
);
SELECT "zone" FROM "grand_canyon_zoning_and_use_limits" WHERE "max_people">23 AND "group_s"<2 AND "name"='robbers roost';