Compound of ᠰᠠᡳᠨ (sain, “excellent”) + ᡥᠣᠯᠣ (holo, “valley”) + ᡶᡠᡵᡩᠠᠨ (furdan, “pass”), calque of Chinese 嘉峪關 / 嘉峪关 (Jiāyùguān).
ᠰᠠᡳᠨᡥᠣᠯᠣᡶᡠᡵᡩᠠᠨ • (sain holo furdan)