It is common modern practice to only file the memo with the county. That is how operators keep specific leasing terms secret (which helps them in negotiations). If you cannot find the full lease that you signed, you can reach out to the landman that you worked with and to the operator directly and request a copy.
They should have had a complete copy of the original lease with their signature and each page of the lease and addendums numbered like Page 1 of 20. Also the Initials of the landman or notary along with the lessor’s. That way you’ll have one. It also would be a good idea to get the company to furnish you a copy with the “in house” signature of the company.
Thank you so much for your help. I am learning so much here. I found it is a very slow process to get answers from antero.