Interesting to note the number of accidents due to this cause over the last 30 years.
-Jan 10 1964, a B-52 bomber, flying at 14,000 ft, 5nm east of Colorado's 13,500 ft Spanish peak, lost about 75% of it's fin and rudder- the gusts exceeded 140 ft per second
-March 5, 1966, a BOAC Boeing 707 broke up in flight at 16,000 ft , 10 nm SE of the summit of Mt. Fuji, Japan.
-August 6, 1966, a Braniff BAC-111 broke up in flight at night near Falls City, Nebraska at only 4,000 ft agl.
-December 2, 1968, a F-27B flying at 11,500 ft, broke up in flight after encountering extreme turbulence at Pedro Bay, Alaska.
In the case of United 585 and the proximity of 14,110 ft Pike's Peak- this could well be the cause(although rudder theory still disputed)