From Steve Schweitzer's A Fly Fishing Guide To Rocky Mountain National Park, flyfishingrmnp.com:
9,000 ft to 9,200 ft
The stretch of the creek has a tad more gradient than the lower section. While you'll mostly find brook trout, in late summer you'll catch a brown or two. Greenback cutthroat also inhabit this stretch, especially if fish are ...
As you enter the Park from the east side and being your trek up Trail Ridge Road, you'll notice a gem of a little stream following and crossing under the road. Plenty of roadside parking pull-outs will give you access to walk the wooded and brush-lined creek. Look for a wood-planked walkway on Trail Ridge Road leading you in the midst of a beaver pond area where there is handicapped fishing access.