From Colorado 160, east of Alamosa, turn north onto Colorado 150 toward Great Sand Dunes National Park. Drive over 3 miles and turn right onto Lake Como road (aka Blanca Peak road). The type of vehicle you are driving will determine how high you can park on Lake Como road. Most cars can drive about 1.5 miles up before it gets rough. 4WD SUVs and trucks can slowly make it 3.25 miles to several pull-offs at 8,800', before the road turns nasty. This is a popular parking spot and gets you within 4 miles of Lake Como. If you have a very high-clearance, small, 4WD vehicle, you can drive higher. An ATV or heavily-modified jeep/crawler can go to Lake Como.
From the start of the Lake Como/Blanca Peak road (Photo #1), it's approx 7.5 miles to Lake Como. See trailhead info (above) to determine how far you can drive.
Here are some photos of the rough sections of this infamous road: Photo #2, Photo #3, Photo #4, Photo #5, Photo #6
Once above 11,400', the road traverses along a rocky slope on the north side of the drainage from Lake Como - Photo #7. Drop down along some angled slabs (Photo #8) to reach the lake at 11,750' - Photo #9, Photo #10, Photo #11. Most people camp south of the lake or farther east along the trail. Photo #12 and Photo #13 are views of the terrain above Lake Como.
A modified, short-wheelbase 4WD vehicle is required to drive all the way to Lake Como. A stock 4WD will not make it and will be damaged. Believe the hype, this is a nasty road.