Mt Inyo is a somewhat nebulous highpoint in the Inyo Mountain Range, slightly overshadowed by its more distinctively pyramidal counterpart, Keynot Peak to the south. The peak is located just south of the Inyo National Forest Boundary and as such, requires nothing but time and effort to climb. It provides wonderful views of the Owens River Valley and once the col is reached, Saline Valley and the Cottonwood Mountains of Death Valley seem to be "just across the way."
The route up is steep and loose which makes for a grunt getting up but once you've bagged the summit (along with Keynot which is practically mandatory if you've slogged it all the way up here) you can look forward to what has been called "the all-time scree descent of the universe." Approximately 4500 vertical ft of perfect scree sized rock patiently await entry into your boots. (hint - bring your gaiters.)
Many people do Inyo and/or Keynot as a dayhike; it can also be done as an overniter as great campsites exist at the Bedsprings Camp. Water can be found at this point in the form of snow depending on season but don't count on it being there.
The climbing from Bedsprings Camp is very enjoyable. Its goes at class 2 (well, maybe a few Cl-3 moves) all the way to the summit blocks and provides fun routefinding to navigate thru the false summits encountered along the way.
from the North end of Lone Pine, go north on 395 1/2 mile and head east on Lone Pine Narrow Gauge Rd (also abbreviated NPLG Rd on some of the signs.) Head east for approx 3 miles staying on the paved road until you get to a "Y" intersection where you will head north for 5 miles. At this point, look for a notch incut into the dirt berm on the east side of the road. Word has it that there used to be some tires piles up here to mark the correct turn. They were not in place when we did this trip.
You should now be able to see the 4WD road heading up Union Wash; this is your objective. A 2WD vehicle will be able to get much of the way up; 4WD will get you another 1/2 mile or so depending on the current conditions and how badly you want to drive it rather than walk. Caution - if you continue in a low clearance vehicle your next oil change may require 1 or more fewer quarts of oil to fill 'er up - watch out for those rocks and ruts.
This peak can be done fairly comfortably in the spring and fall seasons but the odd storm or heat spell can make things unpleasant - as with any peaks, be prepared for inclement weather. When we did this as a DPS trip in May of 2003 we had the spectrum of springtime weather on the ascent - drizzle, rain, snow, the usual.