Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
No measurable cumulative effects have been identified on cultural resources within the planning area.
Past, present and future management actions have avoided and would continue to avoid known sites
(Cultural Resources Report page 3).
Grazing, because it has occurred in the planning area for the past 70 or more years, has likely resulted in
damage to both known and unknown sites. It is likely that both known and unknown sites were damaged
during the early years of grazing, in large part because of the large number of livestock and the periods
during which they grazed. Current grazing practices have not been identified to result in further damage
to such sites. Coupled with current practices of avoidance and/or data recovery, the combination of
grazing and proposed management activities would therefore be expected to have no measurable
cumulative effects on either known or unknown sites (Cultural Resources Report page 4).
Alternatives 1, 2 and 3 would continue the risk of cross-country motorized travel impacting known and
unknown sites until a new motorized travel policy and direction was implemented.
Off Highway Vehicles (OHV)
Existing Condition: The Opine planning area has been used for both casual and competitive OHV
activities since at least the 1960s. Both the Millican Valley OHV system on BLM managed lands north
of the planning area and the East Fort Rock system started from non-designated routes that were used for
events and casual riding. Since the designation and subsequent management of these trail systems, many
of the original trails have been rehabilitated to reduce trail density and impacts to resources. This has also
served to maximize the riders’ experience (OHV Report).
Approximately 23 percent (25,976 acres) of the 114,063 acre East Fort Rock (EFR) trail system is located
within the boundaries of the Opine planning area. This portion includes approximately 100 miles of
designated trails and an additional 28 miles of shared use roads for use by class I and III OHVs (three
wheel, quads and motorcycles). This is approximately 38 percent of the 315 miles of trails and shared use
roads in the EFR system (OHV Report page 2). Use is restricted to designated routes with motorized
cross-country travel prohibited within the trail system area. Use is also restricted to class I and III OHVs
only. The trail system is currently open all year although historically, the system has been closed during
late July and August due to extreme fire conditions. Snow often closes all or portions of the trail system
during winter months.
Approximately 23 percent of the EFR route miles (28 of the approximately 128 miles) located within the
Opine planning area boundaries are shared use roads.
Approximately 30 percent of the users of the EFR trail system use class I OHVs (quads or three
wheelers). With the exception of two difficult trails through the lava, all trails are maintained to
accommodate this type of OHV.
The trail system permits the use of the trails by other users including hikers, mountain bikers, and
horseback riders. EFR has hosted non-motorized events; they typically have not obtained permits so there
is little information available on these events.
Adjacent to the planning area to the north, the Prineville District of the BLM manages the Millican Valley
OHV trail system located north of the planning area. The South Millican portion of this system is located
immediate north of the forest boundary. It contains approximately 43 miles of trails and shared use roads
(designated roads that permit the operation of non-street legal OHVs). This area has a December 1 st to
July 31 st seasonal closure for sage grouse and deer winter range habitat. The area is also often closed by
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