I am a line haul driver with OD in VGS. I'm not on here often, and when I am it's usually just to read, as others always seem to beat me to the right answers. However, I think I can help with this one. Dean has answered the pay question, and as for the number of days working and average mileage, many variables exist. Your flexibility is always the biggest variable. The guys that are always available will work a lot, probably 5-7 days a week.
When I started in VGS 6 years ago, we were in a rented 26 door terminal. About 4 years ago they built us a new 60 door terminal that they are already talking about expanding. We do have a lot of relay freight. Our daytime line haul runs are almost exclusively fed by relay freight, while our night runs are mostly fed by local p&d freight. We have the following scheduled runs.
Day
1x RTO
1x PHX
3x RFU (Richfield, UT meet with GJN) LCV
4x BEA (Beaver, UT meet with SLC) LCV
Night
5x RTO
2x LAS
1x PHX
1x TON (Tonopah, NV meet with RNO) LCV
2x BEA LCV
Along with extra runs to the above, we also frequently go to SGU, and occasionally run direct to ORC and BFL.