For a three day, two night trip in the Rockies during the middles of summer, which is usually only two or three weeks of July, the rest of the year you could very well wake up with frost or snow on the ground like OM mentioned, my gear list is very minimal:

Tent: Contrail (24.5oz)
Bag: MH Phantom +45 Long (19oz)
Pad: Ridgerest short (9oz)
Pack: Conduit (17oz) or G4 (16.5oz)

Total: 69.5oz or a little over 4lbs.

About all that I usually change for the rest of the three-seasons is my bag to a FF Swallow (31oz) and my pad to a Ridgerest Deluxe regular (19oz). Which totals my big four at 91.5oz or a little under 6lbs.

Clothing doesn't change much either: Capilene 1 or 3 (usually worn), Marmot Ion windshirt (usually worn), Yukon down vest, fleece gloves and fleece hat are about the only items I pack consistently. Depending on the expected forecast I will throw in some Cap 2 or 3 bottoms, glove liners, rain mitts, Marmot Precip jacket, Golite Reed rain pants and on those colder days a 300wt fleece may also find its way into the stuff sack.

Cook gear is also simple for three days, two nights: Snow peak 700 with the Caldera Cone UL Compact-- fuel bottle, stove and a mini bic. Food really depends on my mood and company, but for only two solo nights I may just throw in two Mountain House meals for dinner (doesn't seem worth preparing anything at home for such a short period). Breakfast and lunch will be cold: salami, cheese strings, nuts, jerky, cereal/trail bars. If I go for a hot meal then oatmeal for breakfast and some kind of pasta dish for lunch-- if I have my flyrod then it is fish for lunch and dinner-- maybe breakfast also!

I also like coffee, but being originally from England the instant coffee is fine with me, so Nescafe does the trick.