I have kind of a love/hate thing going on for Lost Lake Campgrounds.
Pros: It is beautiful. There's a reason it's one of Oregon's most photographed sites. There's a 3-mile hike around the lake that shows Mt. Hood and its lovely reflection in the lake. There's fishing, swimming, boating, and a camp store that has "It's It" ice cream (definitely a pro). The camp sites are nice, decent sized, and surrounded by trees.
Cons: It is crowded. We're talking thousands of people on a nice summer weekend, traffic jams, and no place to actually make it into the lake (except right at the boat dock) unless you claim your picnic spot really early. There's also no cell phone reception (at all), and while that may sound lovely in theory, when you're a family trying to find each other somewhere on the trail or in the campground it's a real pain.
On weekends and holidays, you also need to book not two, but three nights in a row (Thursday/Friday and Saturday, for example), so if you're trying to get away for a regular 2-day weekend you're out of luck.
In general: 140+ camp sites including several walk-in-only sites right near the lake. There's also cabins and yurts, though those don't include a bathroom on site, so the $70-$150+ seems pretty steep for still having to use an outhouse (we haven't stayed in the cabins personally yet, but have seen them in person). You can book online for both cabins and camp sites (reserveamerica for the camping).
Tips: For day trips, there's a $8 parking fee that you can avoid if you park outside of the entrance and walk the 1/4 mile or so. Also, cabins and yurts are half-price in May, something we may remember for next Memorial Day well in advance (since everything books up so quickly).
We got in late and were very sleepy, so we pitched our tent and didn't look around much. The next morning, we saw all the great mountain views.
Lost Lake is pretty famous and didn't disappoint. Large but private camp sites on a gorgeous lake with a quintessential view of Mt. Hood. You can rent kayaks, canoes, fishing poles, etc. Lots of walk-in sites, however, this spot is very popular so in the high season, you may have the best luck going mid-week or early in the morning to claim a spot.
The sites are large and private, lots of amenities such as trails, boat rental, well equipped store, picnic tables and much more. Beautiful views of Mt Hood and the lake is breathtaking.