In the interests of balance, Sawyers response. Personally, I'm unconvinced that their filter magically knows how to identify whether a given coliform bacterium is harmful or not, and filter only the harmful ones, as they seem to suggest. Furthermore, they very simplistically identify all E.coli as harmful, which is nonsense and makes me wonder if they employ any scientists at all.
I also used Virgin last year for California, SEKI and Inyo - my normal insurance had a 4000m limit for hiking but, bizarrely, not for ski touring and various other activities. My existing insurer confirmed to me that if I carried a pair of skis strapped to my ruscac the whole way I'd be covered but without them I wouldn't be. I've also used Snowcard in the past for climbing and had a very good claims experience with them (albeit 20 yrs ago!).
No permit required for day hikes apart from the Mt Whitney main trail and half dome. The Yosemite overnight permits are a PITA partly because the reservations seem to be mainly (entirely?) by fax, but the vast reduction in JMT permits should, theoretically, free up permits for non-JMT hikers. The Inyo permits entering on the East side, e.g. Mammoth lakes, Bishop, Lone Pine etc. including Mt Whitney, are done on-line through recreation.gov with most bookings opening bang on 6 months before (and some selling out within seconds). Typically its 60% available in advance, 40% walkup. For 1-2 people walkups are usually fine.
Most rescue in that area is free (its usually volunteers, the CHP helicopter or the army), although the medical bills arising won't be.
If you want a nice family backpacking trip we did the 30 miles from Mammoth to Tuolumne meadows (Yosemite), which, mile for mile, is about the most spectacular hiking around. There's even a bus connecting the start and end.