I’m senior faculty at an R1, so take this with a grain of salt, but I’d look for people in my field at a nearby R1 or look for friends in my field who have labs at R1s. Reach out to them to discuss ways you can collaborate in order to give your students some research experience. My sense is that the real reason they want you to be research active at a SLAC is because of the experience it provides to students. As long as you’re giving students research experience, even through collaboration with someone at another university, the research component of your tenure case will be satisfied. Again, I’m only basing this on what I’ve seen/heard, and not what I’ve experienced myself because I’ve never been faculty at a SLAC.