From the exit on I-70 for Silverthorne, (#205) head south on US HWY 6 (aka: Blue River Parkway). The highway north of the interstate becomes State Highway 9, but south of the interstate it's US 6. Drive south and east along US 6 to Keystone, passing several arms or bays of Lake Dillon. As you come to the Keystone Ski area, watch for a right hand turn onto Montezuma Road. The road goes briefly south, passing by some of the parking for the ski area, then heads east and follows along the Snake River. At about 4.6 miles from the turn off US 6, watch for the road to make a sharper left, then right turn. At that right hand turn, make a left turn onto FR 260. This is the Peru Creek Road. Coordinates for the turnoff are: N 39° 35' 31.28" W 105° 52' 15.66". In 1.1 mile, the road crosses Peru Creek. At 2.1 miles is the turnoff for Chihuahua Gulch. There is some limited roadside parking there and back just a short distance on a road that turns south and goes back down across Peru Creek. This is where the route for Lewanee Peak begins. For Ruby Mountain, continue another 2.6 miles to the parking area at the Shoe Basin Mine. This is the Ruby Mtn. trailhead. Shortly beyond here, the road is usually gated.
As you drive up the Peru Creek road, there are several primitive camping sites to choose from on generally National Forest land. You may also be able to get away with a car camp at the parking area for the trailhead. However, there are a large number of old mining claims and private property in-holdings and cabins, so be respectful of any private property postings. There appears to be a good primitive campsite area where FR 263 turns off FR 260 to the south and immediately crosses Peru Creek. See coordinates below. If you need additional ideas about camping, try visiting this website: http://www.townofdillon.com/visit/camping-info. Most Front Range hikers will likely do this as a day hike.