One of the very best things about Lassen is that it is not at all crowded. It's bittersweet, really. We were happy to have few fellow visitors. The trails and viewing areas were not crowded. Yet, it is such a beautiful place, it's a shame more people are not there to enjoy it. It's not a particularly large park as far as national parks go. Certainly not as big as Yellowstone, but it has some of the bubbling mud, sulfur springs, and other features similar to Yellowstone.