How to Propagate Sierra fawn lily?
Propagate by division of established clumps after flowering; re-plant immediately to make sure the bulbs do not dry out

Sierra fawn lily · Erythronium multiscapideum
Plant bulbs in autumn, at least 10cm deep, in fertile, humus-rich, well-drained soil that does not dry out, in light dappled or partial shade, for example in a woodland garden, and mulch each year with leafmould; keep bulbs slightly damp during storage and before planting. See bulb cultivation
Propagate by division of established clumps after flowering; re-plant immediately to make sure the bulbs do not dry out