For the 1st and 2nd Seasons:

Marshall, Will and Holly
On a routine expedition
Met the greatest earthquake ever known
High on the rapids It struck their tiny raft (insert screams here)
And plunged them down a thousand feet below
To the Land of the Lost
To the Land of the Lost
To the Land of the Lost

[CLICK HERE to hear the original Land Of The Lost Theme Song Seasons 1 and 2]

For the 3rd Season:

Will and Holly Marshall
As the earth beneath them trembled
Lost their father through the door of time
Uncle Jack went searching
And found those kids at last
Looking for a way to escape
From the Land of the Lost

[CLICK HERE to hear the original Land Of The Lost Theme Song Season 3]

Ending Credits:

When I look all around
I can't believe the things I've found
Now I need to find my way
I'm lost I'm lost find me
Livin' in the Land of the Lost
Livin' in the Land of the Lost

[CLICK HERE to hear the original Land Of The Lost Ending Credits theme]