I just got back from a wonderful one-night camping trip with Liz and our dog Thor, the first of the summer. We'd been looking for quick-and-easy local campgrounds, and Liz found a hidden gem at Ceran St Vrain. The location's great for us, only 40 minutes from our house in Boulder, just past Jamestown in the mountains. It's got a lot of features to love – it's free with no reservation system, has campsites starting less than a 1/2 mile from the trailhead, there's a beautiful creek running through it, dogs are welcome and and wood fires are allowed. It is primitive camping, so you'll need to purify your water from the stream and there's no restrooms, but I can't imagine an easier introduction to roughing it if you're graduating from car-camping.
To get there from Boulder, you can drive up 36 north of town until you reach Left Hand Canyon Road. You then continue up Left Hand through Jamestown, and then about 10 minutes after the town it switches to dirt. Less than a mile after that, there's a marked turn to the right that takes you past a small ranch house to the trailhead parking lot.
There's only a single trail leading out, which takes you across a small wooden bridge and then follows the creek downstream. After a half-mile, you should start to see the first of the areas people have been using as a campsite. These typically are between the trail and the stream, have a small firepit formed of rocks, and have space for between two and four small tents each. I counted about eight of these areas over the next quarter-mile, and there's also other spaces you could set up tents if those were taken. After that the canyon narrows and the trail heads high up on the side of the bank, so camping's not possible until it heads back down to the water after about half a mile. There's about three more sites with fire-pits in this section, and you can see the one we chose above (wine not included as standard).
If you carry on down the trail, you come to a series of junctions, including a track that theoretically could be used by dirt-bikes and quads, but seemed like it would be extremely challenging. We had two maps with us, and Liz had hiked the area several times previously, but it was still extremely confusing. There's some signs that contradict the names our maps gave for the trails, so make sure you don't attempt them without compass, maps and crossed-fingers.
I'd imagine this area is a popular destination for the locals. Most of the trails are in the canyon or have their views blocked by trees, so it's not Yosemite but it has its own low-key beauty in the pines and creeks. The downside of the lack of reservations is that there's no guarantees on how many people will already be there, but there's a lot of space available so hopefully even on busy weekends you'll be able to find a spot. The parking lot should give you an early warning for how packed it will be too.
It was a fantastic break from civilization, I'm always grateful when Liz manages to pry me away from my laptop, and I'm hoping to drag some more friends out there for quick camping trips over the summer. Maybe we need to make it a Boulder geek event, it's a shame that all these so-called 'camps' take place indoors!