Overview South of US 50 (minus the Canon City area) and west of I-25. Divided into regions according to highway access. SH 149 Silver Thread Scenic Byway from US 50 to US 160 at South Fork. Eastern access to the Alpine Loop. US 550 – the San Juan Skyway – Ouray Area. Western access to the Alpine Loop. SH 145 and the San Juan Skyway – Telluride Area.