Emerald Hill is a fine place to ride! I'll put togeher some direictions really quick:

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Take I-94 to 23. Go SW toward Cold Spring
Take 8 S out of Rockville toward Grand Lake
Follow Grand Lake shoreline to public access (SW side of lake)
Take road that goes west from Public access area. You will know you are on the right road because this road takes you by two radio towers.

We like to park on a side road to the left on the west face of the hill. The name of the road is "Emerald Hill Road"