A Trip advisor review from a trek I did last year:
“We spent a whole day with Sammy in Simien Mountains and went from the entrance as far as Chenek. We saw the famous Gelada Baboos and three Walia Ibex. The landscape was impressive and our hike to the waterfall very nice. Sammy has proven to be a great tour guide and being very knowledgeable. We had a great day and can recommend Sammy for your trip to Simiens.”
https://www.tripadvisor.com/ShowUserReviews-g317059-d12839977-r881641428-Hike_Ethiopia-Gonder_Amhara_Region.html