Percentage of destinations operated by mainline aircraft for AAL/UAL/DAL

GUM (UA) - 100%
ATL (DL) - 88.4%
EWR (UA) - 81.6%
SFO (UA) - 81.6%
SEA (DL) - 79.0%
LAX (DL) - 77.2%
MSP (DL) - 75.4%
MIA (AA) - 75.0%
ORD (UA) - 74.4%
SLC (DL) - 71.2%
JFK (DL) - 73.3%
LAX (UA) - 73.3%
JFK (AA) - 72.3%
IAD (UA) - 71.6%
BOS (DL) - 71.0%
IAH (UA) - 70.0%
PHX (AA) - 69.0%
DFW (AA) - 68.6%
CLT (AA) - 68.5%
LAX (AA) - 66.0%
DTW (DL) - 64.2%
DEN (UA) - 63.4%
PHL (AA) - 60.0%
ORD (AA) - 51.6%
LGA (DL) - 28.7%
LGA (AA) - 25.4%
DCA (AA) - 25.3%

In regards to the thread title this was UAL’s percentage of destinations operated by mainline in the summer of 2019– reference bold

ORD 43.6%
IAH 45.2%
DEN 44%
EWR 55.1%
SFO 69.6%
IAD 41.0%
LAX 62.5%

The fascinating part of these numbers— at this point in time AAL/UAL/DAL have practically the same amount of total mainline aircraft in their fleets.