UA5313 takes numerous routes. The most popular is Eureka, CA (ACV-Arcata - Eureka) to San Francisco, CA (SFO-San Francisco Intl.), which is a direct flight. This service usually takes 1 hour and 9 minutes. That said, there may possibly be other flights with the same number that have one or more stops.
It's more than likely you'll be boarding the Bombardier CRJ if you're taking flight UA5313 from Eureka, CA (ACV-Arcata - Eureka) to San Francisco, CA (SFO-San Francisco Intl.). It's the most commonly used type of aircraft on this busy route.