@anthony1312002,
My wife and I are going on a trip and tour to Yosemite later this month, and I was looking for tipping guidelines. Many people in the service industry gave their input, and it seems many people do not tip them. I was amazed, because I've been traveling for most of my adult life, and I always leave it a tip for people who have provided me with a service including tour bus drivers.
I don't even rate that as gratitude as much as a necessity for folks who work for minimum wage. Even Tour Directors can't make a living just from their salary. They depend on tips to make a living.
I used to leave a tip for the housekeeping staff after my stay, but learned long ago that staying at the same hotel for a few days may mean a different housekeeping staff servicing your room, so I now leave a tip every day with a note; HOUSEKEEPING Thank you. $$.