The Strip is better than you think
Every major Strip resort is fully ADA-compliant: level entries, roll-in showers on request, wide gaming aisles, accessible pool lifts, and Braille signage at elevators. The pedestrian bridges at the main intersections (Tropicana, Flamingo, Spring Mountain) all have elevators, though at least one is usually out of service, so build in an extra 10 minutes. The Monorail is fully accessible with level boarding, and the Deuce bus has kneeling ramps.
Rideshare wheelchair-accessible vehicles (Uber WAV, Lyft Access) exist in Vegas but wait times run 20-45 minutes, much longer than standard. If you need WAV consistently, prebook with a specialist operator like ExecuCar or CLS. Taxis are required to dispatch accessible cabs on request but the fleet is small; call 30 minutes ahead.
The four things that catch people out
First: distances inside resorts. From the Aria porte-cochère to the Aria pool is nearly half a mile of indoor walking. Ask the bell desk for a wheelchair loan (free at every major property) even if you normally walk; save your energy for the actual attraction. Second: casino carpet is thick and hard to self-propel; power chairs handle it fine, manual chairs struggle after an hour.
Third: shows. Every Strip theater has accessible seating but the good sightlines go fast; book by phone with the box office, not through Ticketmaster, and ask for row placement. Fourth: the outdoor attractions. Red Rock Canyon scenic drive is drive-through accessible with paved overlooks, but almost no trails are. Valley of Fire has one accessible overlook (Rainbow Vista). Hoover Dam tours have full elevator access; the powerplant tour, not the shorter dam tour, is the accessible one.
Beyond Vegas
Reno's downtown casino strip is compact and mostly accessible, and Lake Tahoe's south shore has paved lakefront paths at Nevada Beach and Zephyr Cove. The gondola at Heavenly is wheelchair accessible to the observation deck. Great Basin National Park has one accessible trail (Mountain View Nature Trail) and accessible cabin campsites at Upper Lehman.
Rural Nevada is the harder story. Historic districts in Virginia City and Genoa have boardwalks with steps and lips, few curb cuts, and steep grades. Small-town motels are often grandfathered out of full ADA compliance. Call ahead and ask specifically about roll-in showers and door widths; "accessible" can mean a grab bar and nothing else.
Good to know
Are the fountains at Bellagio wheelchair accessible?+
Yes, the entire viewing rail along Las Vegas Boulevard is level, and there's accessible seating inside the resort at the fountain-view lounge windows.
Can I rent a mobility scooter for the trip?+
Yes. Scootaround and Cloud of Goods deliver to any Strip hotel, roughly $50/day or $200/week, and every major resort holds them at bell services.