Review: 

We have enjoyed all of the Colorado State Parks we have visited, and St. Vrain is another strong contender. Though located right next to the I-25 freeway, and therefore somewhat noisy, the campground has multiple sites on small lakes, grass, shrubs and trees, sheltered picnic tables, concrete slabs for the RVs, and tons of space between sites.

We saw deer and prairie dogs near the park entrance. There are bike and walking paths all around the little ponds and throughout the state park.
Site #46 is right on Bald Eagle Pond with lovely views all around. If we came again, we would try to get a site further from the freeway and with more shade trees. Here are some sites we think are good: Coot Loop is further from the freeway–#67, 68, 72. Mallard Pond loop is electric only—sites #36 and 40. Any site in Pelican Pond (electric only) loop—these are the most shaded but closest to the freeway.

Otherwise, we loved this campground and would definitely stay here again if we were in the Boulder/Longmont area. It’s a decent base for day trips to Rocky Mountain National Park. There is a Camping World nearby. You are close to the St. Vrain Greenway bike path that begins at Sandstone Ranch Visitors Center.