is the roadrunner bird native to the sacramento valley, ca?

I found a bird checklist for the Sacramento National Wildlife Refuge Complex, 
which lists all the birds seen in six wildlife refuges in the Sacramento 
Valley.  The checklist lists roadrunner sightings as "accidental", the lowest 
frequency of sightings on their checklist.  However, according to the checklist 
roadrunners are present in the Sacramento Valley during all four seasons of the 
year, while some other birds have dash marks indicating that they aren't 
present during certain seasons at all.  So, while there are roadrunners in the 
Sacramento Valley, you were lucky to get to see one - if I'm reading the chart 
correctly, there are only between 1 and 10 roadrunner sightings each season in 
the Sacramento wildlife refuge.  As the map in the comments indicates, 
roadrunners are more common in the drier areas of the Southwest.

Here is the Sacramento National Wildlife Refuge Complex bird checklist:
http://www.npwrc.usgs.gov/resource/othrdata/chekbird/r1/sacramen.htm

I hope this answers your question!

http://www.utep.edu/~leb/images/maproad.gif

This is Geographic range of the Greater Roadrunner[Geococcyx californianus] in 
the USA; its range continues south into northern Mexico.

Thanks for the map.... Some more background... I'm in a suburb north of 
Sacramento. Saturday, I was standing in my garage and noticed what appeared to 
be a road runner walk into my front yard. He nibbled around a bit in the grass. 
Saw me, flipped up his comb, turned and "ran" off. I've never seen one in this 
area.

As others have said, they certainly aren't common, but we've seen one in
the western foothills about 75 miles north of Sacramento.  We were equally
surprised!  :)