Yes, you can go to the West Rim of the Grand Canyon without a tourist company. It is about a two hour drive from Las Vegas. You must take route 93 south across Boulder Dam into Arizona in the direction of Kingman. Before you reach Kingman, you must turn east on some secondary roads toward the Hualapai Indian Reservation. Part of the way, the road gets rough and unpaved but it is always passable. The scenery along the way is beautiful.
At the Hualapai Reservation, you will find a small visitor's center with a helicopter landing pad, a small gift shop and a small restaurant. There will be an admission fee for entering the reservation and a fee for using the skywalk. The Hualapai Indians that own this small section of the Lower Grand Canyon use it as a tourist attraction and a source of income for their tribe.
I will post your message and this reply on our bulletin board, as other readers might have the same question.
Mike Leco