I'm not a bluegrass banjo player, I'm an old time music clawhammer style player. So Cripple Creek is not in my repertoire. Of course I'm familiar with the tune, and to answer your question about the difficulty level on guitar...hmmm, I'd guess about a 6 on a 1-to-10 scale. Definitely a flat pick tune... I play guitar too, and prefer finger picking, but that tune just begs for a flat pick. I imagine any decent guitar teacher cold get you started on mastering that tune.

BTW, if you're not familiar with clawhammer style, let me refer you to Steve Martin's Clawhammer Medley: https://www.youtube.com/watch?v=sovTfNH4Lag

...and my all-time favorite Old Time tune, Julianne Johnson, which I've played for a local movie production: https://www.youtube.com/watch?v=uyXhu3dZUHw

Follow up answer: I realized I threw out the phrase "Old Time music" and realized that not a lot of people know what that is. Old Time is generally mostly fiddle music that came to the Americas from the British Isles in 1700s and 1800s. It took root in Appalachia, but also in the midwest and northern states to a lesser degree. Old Time was heard throughout Appalachia from the early 1800s well into the early 20th century.

Then the music (and instruments...fiddle, banjo, guitar) followed the western expansion and could be heard throughout the old west. Old Time follows a pattern of 8 measures that are repeated, for 16 measures in the A Part; then 8 measures (twice, for 16 measures) in the B Part, and then it's repeated over and over until the leader calls a stop.

This was mostly dance music and the only music the people of that time had for dances. I play it today to keep the sound alive. My own grandfather in the early 1900s was an old time fiddler and met his wife (my grandmother) while playing at a square dance in rural, remote east Tennessee. He was also a Spanish American War veteran.

Here is another Old Time tune played by a trio out in Utah...I dare you listen to it and not smile. Enjoy:

https://www.youtube.com/watch?v=MrUk8tpL7tQ