There are two obvious access points to Rattlesnake Mountain that should NOT be used. The first is the network of trails seen on the Alltrails app starting off Garnet Valley Road. This is private land and the landowner will ask you to leave. The second is seen on various Summerland city literature with trailhead at the end of Cristante Road. There is a locked impassible gate at the end of Cristante Road with no access.
Some have been parking along Sandborn Road where the new Hunting Hills subdivision is under construction. Many report having no issues starting here but officially it is not allowed because of ongoing construction. Use at your own risk.
A potential access point (not verified yet) would be to try accessing off Garnet Valley Road 1.2km north of Jones Flat Rd. Parcel 18654 is municipal land (search here) designated as park so theoretically should avoid any private land (but nearby parking is an issue).
See the google map below for more details on all access related issues.
Important Trail Information
There is no trail up Rattlesnake Mountain. Route-finding is necessary although this is not so hard as there is very little undergrowth. At times the Goat Trail (mountain bike trail) heads in a useful direction for hikers and at other times animal trails are available. There are no obvious trails close to the ‘summit.’
There are viewpoints at the top of Rattlesnake Mountain over the beautiful Garnet Valley as well as in every other direction across the Okanagan. The rugged cliffs at the west side of the mountain are of particular interest.
The hike (using route highlighted on the google map) is approximately 9km round trip and takes around 3 hours.
GPS Download: GPX