SOUTH PLATTE RIVER IN SOUTH PARK: One of Colorado’s best for quality-sized rainbow, brown and cutthroat trout. Best areas are between Spinney Mountain and Elevenmile reservoirs, upstream from Spinney, the Middle Fork from the confluence with the South Fork upstream to Fairplay and the South Fork above Antero Reservoir to Highway 285. Best kept secret: Elevenmile Canyon. Location: West of Colorado Springs on Highway 24.