NMAC.

Narrative

SCHEDULED FLT FROM PHX; AZ; TO GJT; CO; DECISION MADE TO STAY LOW TO AVOID EXCESSIVE HEAD WINDS. CRUISING LEVEL 13.5; AFTER MODERATE CHOP AND UPSLOPING CLOUD BASES (SCATTERED) DECISION MADE TO CLB TO 15.5. DURING CLB; ATC TA STATES 'TFC 11 O'CLOCK AND 8 MI CLBING OUT OF 1500 FT.' DECISION WAS MADE TO SLOW CLB AT 14.5 (APPROX 200 FPM). TFC ALSO ISSUED TO OTHER PLT (NO RESPONSE). ABOUT 50 SECONDS LATER OTHER ACFT SUDDENLY APPEARED XING L TO R (AT ABOUT A 90 DEG ANGLE) NO FURTHER THAN 35 FT FROM THE FRONT OF THE ACFT. THIS INCIDENT WAS THE RESULT OF 3 DIFFERENT PARTIES NOT HAVING A CLR IDEA OF WHAT WAS ABOUT TO HAPPEN. PLT OF OTHER ACFT (SMA Y) DID NOT ACKNOWLEDGE ATC WHEN GIVEN TA. UNDER THE PREMISE THAT ALL ACFT MUST BE VIGILANT UNDER VFR FLT RULES; THIS WAS A TIMELY AND IMPORTANT MESSAGE WHICH SHOULD HAVE BEEN ACKNOWLEDGED. ATC GAVE TFC INFO; BUT WHEN THE TIME CAME FOR CRITICAL EVASIVE ACTION; NO 'TFC ALERT' INFO WAS GIVEN. FLC OF OUR ACFT SIMPLY DID NOT PICK OUT THE TFC IN TIME AND SEEMED TO BE RELYING TOO MUCH ON ATC AND THE OTHER PLT FOR THEIR PARTS IN REMAINING SEPARATED.