randy
b6a9c1546e
A ruler button in the top-left control stack, matching NPS's own Area/Distance ruler. Click to add vertices; distance sums haversine segment lengths, area uses the spherical-excess polygon formula (same one turf.js's area() uses) rather than a flat shoelace, since a flat approximation drifts at park-boundary scale. SI units only (m/km, m²/km²) — no imperial toggle.