I was struggling to find a pet-friendly rental near Lassen National Park and am so happy to have finally found Hat Creek Resort. We stayed in a cabin that was comfy and cozy - really appreciated the extra pillows and blankets, as it got quite cold at night! (Although there is heat as well). I was also extremely impressed by how well-stocked the kitchen was. We cooked on the pit fire outside every night because we wanted to, but nothing would have been lacking had we wanted to cook indoors (which is very rare for a rental, particularly a cabin).
The river running through is lovely and the view of the stars and Milky Way at night is stunning. The cabins are right off the highway, but that was fine with us as we appreciated the easy access to the park.
The on-site store is good for emergencies, but it's quite limited and closes early so I suggest bringing everything you need! It's a long way to the nearest place for any other supplies you might need.
Overall a fantastic experience and would happily stay again :)