As of March 2017[update], the wilderness was inaccessible to the public without trespassing, as it and adjoining state-owned property were entirely surrounded by privately owned land.

In 2021, the size of the wilderness was increased by 9,855 acres (39.88 km2) with a donation from the Trust for Public Land which acquired the former Hobo Ranch.

[6] Sabinoso was finally established as part of the Omnibus Public Lands Management Act of 2009, signed into law by Barack Obama on March 30, 2009.

[11] The northeastern corner of the wilderness area is near the Canadian River and the 1890s settlement of Sabinoso, now mostly abandoned except for a few remaining buildings.

These rocks are almost entirely sandstones, siltstones, and shales, and represent geological time from the Late Triassic to the Early Cretaceous epochs.

[11] Sabinoso Wilderness Area is surrounded by privately owned land and initially had no route for public access.

[15] About a dozen state-owned parcels of land adjoin Sabinoso, but they are themselves also "landlocked," entirely surrounded by privately owned property.

[16] In 2016 the Wilderness Land Trust, financed by the Wyss Foundation, purchased the 4,080 acres (16.5 km2) Rimrock Rose Ranch for $3,150,000 with the goal of enabling public access to the area.

[17] The environmental evaluations needed before visitors would be allowed to enter the park, were estimated to require up to a year to complete, and were made available for public comment as of August 2016.

[18][19] In August 2016, The Bureau of Land Management proposed to accept a donation of 3,314 acres (13.41 km2) of the Rimrock Rose Ranch for addition to the Wilderness Area.

"[22] On July 17, 2021, Secretary of the Interior Debra Haaland accepted a donation of 9,855 acres, which both increased the size of the designated wilderness area by about 50% and provided for a second public access point.