Butte County is an easy county to monitor, with most everything in VHF with the exception of oddball Chico City Fire - which is UHF, and the only UHF fire agency north of Sacramento that I know of. The common radio spots for the county include Mt. St. John on the opposite side of the valley and Platte Mtn above Chico. All the law enforcement agencies can talk on each other's radio systems and CHP mobiles are simulcast on the Base channel. Search and Rescue is a large part of Butte County.
An odd part to Butte County is the interagency link. This is a lowband frequency that seems to be interlinked with most agencies in Butte County. The only time I've heard it active was Enloe Flightcare contacting CDF ECC for an update in the incident location. This after the copter wasn't answering on local net or it's own net. So make sure you plug in Butte Interagency to hear some behind the scenes action.
Butte Fire can be pretty active. Lately the Jarbo Gap has burned a few times and ended up being the most destructive fire(?) in Butte's history last year (I did ARES radio traffic then). Years before they had trouble keeping Table Mtn fire free. As for law - Chico is a university town. So the night life is much better than areas such as Redding (take that from a 23 year old familiar with both ;) Holloween and St Patricks Day offer non-stop Chico PD fun. Be sure to monitor the mutual aid freqs - and all in between.