Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets.
In a large bowl, cream together butter, brown sugar and white sugar until smooth. Beat in eggs and vanilla. Combine flour, baking soda, and salt; stir into the creamed mixture. Mix in the oats, chocolate chips, raisins, and pecans, one ingredient at a time. Drop by rounded spoonfuls onto the prepared cookie sheets.
Bake for 8 to 10 minutes in the preheated oven. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.
