The US 97: Spanish Hollow Cr. (Mud Hollow Road) Bridge is owned and maintained by the Oregon Department of Transportation and provides access from US 97 to Mud Hollow Road. Mud Hollow Road is owned and maintained by Sherman County. The bridge was built in 1962 but severely damaged in the 1964 flood and later repaired. Routine inspections of the bridge have discovered some scour (erosion of the streambed) beginning to occur around the foundations and therefore the bridge was programmed into the 2012 – 2015 Statewide Transportation Improvement Program (STIP) for “Scour Repair”. The programmed amount for the project is $569,000.
During recent initiation work by ODOT and Sherman County to review and verify the scope of the project, it was determined that other options may exist, up to and including removal of the bridge and the closure of Mud Hollow Road at US 97.
- Average Daily Traffic on Mud Hollow Road at the bridge is unknown at this time, but reportedly extremely low use. There are two residences along Mud Hollow Road.
- Intersection site distance at the Mud Hollow Road approach to US 97 is substandard to the south. To correct this problem would require a significant amount of excavation along US 97 to increase sight distance. Fortunately there are no reported accidents at this intersection, likely due in large part to the extremely low use of the approach.
- From the northern-most house on Mud Hollow Road to the intersection with US 97 to the north is 1.5 miles. If Mud Hollow Road were closed at US 97, it would require those residents to drive an additional 8 miles to reach that intersection.
- The lower portion of Mud Hollow Road was paved by Sherman County as a means to address difficult maintenance issues in this narrow canyon section. If this portion of the road remains open, costly maintenance repairs by the county are anticipated in the coming years.
- Sherman County Sherriff has indicated that closure of the northern approach to Mud Hollow Road would not adversely affect law enforcement, and may in fact reduce the potential for some undesirable activity that has been known to occur along Mud Hollow Road in the past.
- Sherman County Emergency Service providers are concerned over the potential closure of Mud Hollow Road at US 97 because this provides an alternate access to an area. They feel that the closure of Mud Hollow Road at US 97 could increase response time for ambulance or fire services in some situations.
Perform the scour protection on the bridge as it is programmed in the STIP. Under this alternative, ODOT continues to inspect and maintain the bridge into the future. Mud Hollow Road would remain open and Sherman County continues to maintain the entire length of the road into the future.
Remove the bridge and close Mud Hollow Road at US 97. Use the funds programed for the bridge scour work to remove the bridge and upgrade the alternate routes to the south (upper portion of Mud Hollow Road and Locust Grove Lane). This alternative would reduce or eliminate future costs to ODOT and Sherman County (and to Oregon taxpayers) for inspections and maintenance of a low use bridge and Mud Hollow Road.
Two other alternatives were discussed: do nothing at this time, or limit access to the bridge for emergency purposes only with a gated approach. It was felt that both of these options simply postponed the decision to the future and the current funding would be lost, so they were set aside from further consideration.
What Was Decided
Based on public input, ODOT and Sherman County decided to leave the bridge in place and to do a scour repair later this year.