Do I need a permit for ev charger installation in Mammoth?

Most likely yes. Ev charger installation usually requires a permit in Arizona. Confirm the specifics with Mammoth.

A new 240-volt circuit or hardwired charger is permitted and inspected locally. Cities and towns adopt their own codes, and a county may adopt an electrical code for its zoned unincorporated areas (ARS 11-861). A county's electrical, plumbing, and mechanical codes may be a national model code or the code adopted by the largest city in that county (ARS 11-861), so the edition and inspection steps differ across the state. Arizona's small-job licensing exemption (ARS 32-1121, subsection A, paragraph 14) covers only casual or minor work under $1,000 in total and does not apply to any job that requires a local building permit, so a hired contractor on permitted work must hold a Registrar of Contractors license. This installation adds a 240-volt circuit or a hardwired charger, or changes the electrical panel. New circuits and panel work are electrical work that normally needs an electrical permit and inspection wherever an electrical permit program exists. A panel upgrade or new service usually also involves your electric utility, which may need to disconnect and reconnect power, so call them early. Many places require a licensed electrician for this work. Where a homeowner may do their own wiring, the permit and inspection still apply.