Definitely not for trail runners.
This singletrack goes from the Boo Hoff Trail
to the Cactus Spring Trail
. It is likely an old Cahuilla Indian Trail that has also been used by those moving seasonally from the desert below to the cooler mountains above. Although the trail crosses three to four creeks/drainages, there is likely no water along the route so you need to carry plenty. The Guadalupe Trail is listed as an "unmaintained" trail by the Santa Rosa National Monument map and it is very difficult to follow if you are not careful. It was recommended by some experienced runners in this area to follow the trail uphill as it is easier to follow. The only way to succeed is by keeping a keen eye out for "ducks" or cairns (two to three stacked rocks) that mark most of the trail.
At around 4,500 feet, you'll encounter an old "Cowboy" camp that is located along the Guadalupe Creek. At this point, there are very few trail markers, but the trail follows the sandy wash of the very intermittent stream bed up to the saddle or pass between an unnamed peak of 5,122 feet and Martinez Mountain which is 6,562 feet. The pass is at about 4,900 feet. You'll continue west-southwest from the pass and will then follow another sandy wash to the intersection of the Cactus Springs Trail. During the climb, you'll have great views of the Coachella Valley below, including a full view of the La Quinta Cove. To the east is the Salton Sea and to the north is Joshua Tree National Park. You'll also experience changes in scenery as you transition from Cholla, Barrel Cactus, Yucca Trees, and Ocotillos, to Pinyon Pines and Jojoba. While I did not encounter any wildlife other than birds and lizards, the area is inhabited by rattlesnakes, mountain lions, Bighorn sheep, and other species common to the region.
It is best to use this trail during the cooler winter months as mid summer would be brutally hot. Although this lightly used route has the advantages of great solitude, there is cell phone service most of the way up the mountain as there is a clear view of the valley below. The most difficult part of the trail was crossing the stream at about 3,200 feet. There is a very obvious trail marker above the creek, but from there you have to search carefully for the next marker for the route down to the creek bed and out again. This GPS route has been uploaded specifically to help others navigate their way as this trip is much easier with the GPS track than without it.
Cholla, Barrel Cactus, Ocotillo, Yucca, Jojoba and Pinyon Pines are all along the route. It is most likely you'll see birds and lizards along the way and it is possible, but not likely, to see a Rattlesnake (depending upon season), a Mountain lion, or Bighorn sheep.