Swissco Area, Idaho Springs Reservoir, also noted in Indian Peaks Bouldering

Drive I-70 a few miles west of Idaho Springs to the Fall River Road exit, head north for several miles, approximately 9, towards St. Mary Glacier. At a hairpin turn, look for Rainbow Road, hang a left on this dirt road and wind your way up, 4 wheel, bumpy, but accessible, towards the reservoir, several miles. You'll pass many primitive campgrounds, before reaching the reservoir. Park at south end of the reservoir, and hike around the reservoir's right, east side following a single trailway to the opposite end of the reservoir. At the opposite end, head up on the right side of the waterfall and creek eventually crossing over towards the top. Continue up, usually wild flower gardens, into the open basin, and you will see the granite boulders up on the left, as well as some on the right side of the basin. It can be very snowy til mid or the end of summer.