The Marshall family were the central characters from the 1974-1977 children's television series Land of the Lost. The original family consisted of father Rick Marshall, son Will Marshall and daughter Holly Marshall. This iteration of the family was featured in the first thirty episodes of the series. Following the season two episode "Blackout", the character of Rick Marshall was replaced with that of Uncle Jack, who remained on the series throughout the remainder of it's run. The 2009 Land of the Lost film re-imagined the character concepts of Rick, Will and Holly, however none of these characters were related to one another.
In the year 1974, the Marshall family embarked upon an ill-fated rafting trip - a trip they believed would just be a "routine expedition". While shooting the rapids, an earthquake tore through the area, dropping giant stone slabs into the river. Their raft went over a waterfall and plunged them down a thousand feet through an interdimensional doorway. All three Marshalls survived the plummet, but when they awakened, they found themselves stranded on another world - a world ruled by dinosaurs, primitive hominid life forms and reptilian insect warriors known as Sleestaks. To escape the advances of a hungry Tyrannosaur, which they named Grumpy, the Marshalls sought shelter in a cave on a high bluff.
An intelligent and pragmatic man, Rick Marshall, understood that the key to their survival was dependent upon their ability to adapt to their surroundings. He taught Will and Holly how to forage for food, but more over, how to avoid becoming a snack for the likes of Grumpy and other dinosaurs that inhabited this "Land of the Lost".
Rick was never satisfied with simply surviving in the Land of the Lost however. He was confident that they key to returning home could be found if one knew where to look for it. In contrast to the savage environment in which they now lived, Rick discovered evidence of a technologically advanced civilization - one that lived on this world many years ago - a race whose accomplishments included the construction of a stone monolith called a Pylon, which contained a crystal table, capable of many extraordinary things.
Though life was always dangerous for the Marshalls, it was not without merit. Rick befriended a primitive, young cave boy named Cha-Ka, who was a member of a race called the Pakuni. When Rick first came upon Cha-Ka, he found that the boy had fractured his leg while trying to escape from Grumpy. Rick set his leg in a splint and helped him to recover. From that moment forward, Cha-Ka was a friend to the Marshalls. 
In their quest to learn more about the world around them, Rick and the children discovered the Lost City - a series of ancient temples located on the opposite side of a great crevasse. The Lost City was home to the Sleestaks - nocturnal hunters who stalked the dark environs of the city with their crossbows in search of prey.
They also befriended another strange being named Enik. Enik was an Altrusian and an ancestor of the modern-day Sleestaks. Like him, Enik had come to the Land of the Lost through a dimensional doorway and was trapped. However, Enik possessed great knowledge concerning the Pylon and the glowing light crystals that were found within the tunnels beneath the temple. He showed Rick, Will and Holly how the light crystals could be used to protect themselves from the Sleestaks.