New Lease South of Cheyenne

Got an unsolicited lease in the mail offering $300 per acre for land south of Cheyenne, east of 85 and just south of Chalk Bluff road. Is this reasonable?

What is the legal description?

What is the length of the lease and the percent royalty? I have heard of recent leases east of you going for 500/acre and 18% for 5 yrs.

Conco is offering $800/acre and 18% royalties for this area.

What companies are offering leases east of Cheyenne, near Hillsdale. We have an offer from Silo Oil. Any one hear of them?