
Just off the trail were several of these mounds built by dusky-footed woodrats. They were typically three to four feet tall, sometimes taller - most over a meter. They are native to California.
These mounds typically contain a living space with other small spaces in which they store food, sometimes called 'pantry chambers".
Neotoma fuscipes are not closely related to the common rat, Ratus ratus, which is native to India/Pakistan. The Neotoma fuscipes have a similar appearance but have larger ears and eyes, softer coats, and furred tails. (For more see this inaturalist page on our Dusky-footed neighbors.)
In 1994 the FWS ranked this species as category 2, which they described as "Taxa for which information now in the possession of the Service indicates that proposing to list as endangered or threatened is possibly appropriate, but for which persuasive data on biological vulnerability and threat are not currently available to support proposed rules." ecos.fws.gov