Interstate vs Intrastate Commerce

Is a regular route bus service between Reno and Phoenix, making a stop at Las Vegas, considered interstate or intrastate commerce?

According to FMCSA: What is the difference between interstate commerce and intrastate commerce?...
"If you perform trade, traffic, or transportation exclusively in your business’s domicile state, this is considered intrastate commerce.

If your trade, traffic, or transportation is one of the following, this is considered interstate commerce. Source: 49 CFR 390.5.:

• Between a place in a state and a place outside of such state (including a place outside of the United States)
• Between two places in a state through another state or a place outside of the United States
• Between two places in a state as part of trade, traffic, or transportation originating or terminating outside the state or the United States"

Obviously, such Reno to Phoenix route would be interstate commerce. But what if a passenger gets on at Reno and gets off at Las Vegas? Would this be considered intrastate commerce in addition to interstate commerce?

When I asked the FMCSA, they said "no" and confirmed in writing in an e-mail, because such Reno to Las Vegas passenger is still "part of trade, traffic, or transportation originating or terminating outside the state" because the bus is operating a Reno to Phoenix route. Does this mean only interstate regulations apply to such route?

 

Exactly, that's why I thought it would be interstate. But is it intrastate in addition to interstate if a passenger jumps off at Las Vegas?

• When I called PUC they said bus operations are not under the purview of PUC.
• When I called state DOT they gave me an ambiguous answer (they told me to send an e-mail, but never responded to the email).
• When I called USDOT they said I only need interstate authority.
• When I asked an attorney he said I only need USDOT authority.
• When I asked Greyhound about their Reno - Denver route which stopped at Winnemucca and Elko, they said they only have a license from Nevada for "intrastate charter bus service", but that such license doesn't include the Reno - Denver, which is regular route, not charter, and not intrastate.

I have no reasonable means of preventing a passenger from getting off at Las Vegas.

 

• We drive from Reno to Las Vegas.
• We take a few minutes break at Las Vegas, change drivers.
• We keep driving to Phoenix.
• We turn around next morning, load up, drive back to Las Vegas.
• We take a few minutes break at Las Vegas, change drivers.
• We drive home to Reno.

Interstate, right? But do I also need to deal with intrastate on top of interstate? The route is Reno to Phoenix, we just took a break at Las Vegas. But passengers could get on or off at Las Vegas.