Along with Guanella Pass and the Longs Peak trailhead, this is one of the most popular trailheads in Colorado. On summer weekends, the parking lot fills up by 6:30 or 7am, and before long, the cars are lined up along the road for a mile or more.
Camping is available at the trailhead, but on a busy summer weekend, you may have trouble getting a campsite.
Restrooms are available at the trailhead.
Take exit 221 (the Bakerville exit) from I-70. This exit is a few miles after Silverplume when coming from the east, and a few miles from the Eisenhower Tunnel when approaching from the west.
If it is winter, you will probably be starting your climb from here, an elevation of about 9,800 feet. Otherwise, follow the signs on the south side of the highway pointing to Grays Peak. It is well marked, but you should be sure to bear left at the fork in the road. The trailhead is about three miles from Interstate 70.
The road gets rough in places, but so long as you have decent clearance and are experienced driving rough roads, you should be able to make it to the trailhead, even in a passenger car. Be aware, though, that the road conditions can change from year to year, and the road is not maintained. If you only have a low clearance vehicle, you may want to consider leaving it at the bottom of the road and hitching a ride to the trailhead. Given the traffic that this area receives in the summer, you shouldn't have any trouble finding a ride.